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  • richardmitnick 3:01 pm on June 16, 2018 Permalink | Reply
    Tags: , , , , Dealing with Science Data at ESO, ESOblog   

    From ESOblog: “Dealing with Science Data” 

    ESO 50 Large

    From ESOblog

    15 June 2018

    ESO is proud of being the most productive ground-based observatory in the world, making observations that led to over one thousand scientific papers in 2017 alone. But to produce such a huge number of papers, ESO’s telescopes must churn out mind-boggling amounts of data. So where is all this data stored and how do astronomers get their hands on it? We spoke to Martino Romaniello, Head of the Back-end Operations Department at ESO Headquarters, to find out.

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    Science@ESO

    Q: Martino, tell us a bit about your role at ESO.

    A: I joined ESO in late 1998 as a postdoctoral fellow, fresh out of my PhD at the Scuola Normale Superiore in Pisa, Italy and the Space Telescope Science Institute in Baltimore, USA, the “home” of the Hubble Space Telescope. Those were the early days of science operations with ESO’s Very Large Telescope and I was immediately transfixed with the scale and ambition of the project, and of how much it aimed to change the paradigm of ground-based astronomy. I became an ESO staff member in the year 2000, sharing my time between functional duties for ESO and research as a member of the Science Faculty.

    For functional duties, I served as a Support Astronomer until 2006. Since then, I have led different organisational units that dealt with the handling of science data. In our latest incarnation as Back-end Operations Department, we are responsible for the “last mile” of the long journey of science data, namely that the science content is there in the data, that it can be extracted and calibrated, and that it is made available to our community in a scientifically meaningful way through the ESO Science Archive.

    In my own research, I am interested in the formation and evolution of stars, both as individual objects and in stellar systems. Specifically, I use a particular type of stars called Cepheids to gather hints on what might be driving the accelerated expansion of the Universe.

    Q: What data does ESO make available to the community?

    A: ESO makes all of the data generated by our telescopes that has scientific relevance openly available to the science community around the world. Preventing data from being accessible is the absolute exception and is reserved to cases such as the very early phases of commissioning of new instruments or other similar test phases in which the data has no scientific content to speak of.

    In order to be useful for scientific measurements, the raw data acquired at the telescopes have to be processed to remove the signatures of the measurement process (from the telescope, instrument or Earth’s atmosphere) and extract and calibrate the science signal. In addition to the raw data, we also provide processed data directly through the archive. The availability of processed data for science analysis is specifically important to making the archive useful for the general community and increasing ESO’s overall scientific return.

    Q: How much data is currently stored and where?

    A: The data from the La Silla and Paranal Observatories amounts to a bit more than one petabyte (equal to one million gigabytes), and we store copies for redundancy and safety reasons. Two of these copies are in different locations at ESO Headquarters in Garching, Germany. The third one is hosted by the Max Planck Computing and Data Facility at the Garching Research Campus. The homepage of the ESO Science Archive is at http://www.archive.eso.org. ESO also host the European copy of the ALMA Science Archive at https://almascience.eso.org/alma-data/archive.

    Data storage and exchange technologies are rapidly evolving, pushed by the increasing demands of scientific and commercial endeavours. We actively partner with the likes of ALMA, CERN and the Square Kilometre Telescope (SKA) to cater for our needs in the most efficient way possible.

    SKA Square Kilometer Array

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    The ESO Science Archive is located at ESO Headquarters in Garching, Germany. It was developed in partnership with the Space Telescope – European Coordinating Facility (ST-ECF) and operated jointly until the closure of the ST-ECF in December 2010. It holds the astronomical data produced by the La Silla and Paranal Observatories and makes them available to the public. Over 1 Pb are stored in the disk servers like those seen on this photo. Credit: ESO/H.H.Heyer

    Q: Why is ESO’s data available as open access for anyone to use? Has it always been that way?

    A: Open access to data is a staple of scientific research and serves several purposes. The first is that it enables any scientific claim to be independently verified and challenged, which is a founding principle of the scientific method. Secondly, it allows for genuinely new science and knowledge to come from the data. This is both in conjunction with other data, or by using the archive as a primary source. In addition, archival data is used to design better experiments that require new data to be obtained. In fact, in order to apply for observing time with any of ESO’s telescopes, astronomers need to show that their proposed science goals cannot be achieved with data already available in the archives — this is much quicker, as applying for and receiving new data can take as long as one to two years.

    ESO’s data open access policy can be traced back to 1988 with the introduction of “Key Programmes” on La Silla. Open access to data has been ingrained in the science operations policy of the Very Large Telescope and its interferometer since the very beginning of science operations in 1999. Initially, access was limited to ESO Member States. Following a decision by the ESO Council in December 2004, the archive was opened to the whole world on 1 April 2005.

    A recent science paper described the ESO Science Archive as the “largest telescope facility ever.” While it may be a bit of a hyperbole, it does convey the power of reusing data collected over decades from some of the most powerful telescopes and instruments ever built.

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    These servers help provide access to the science data archive. This picture was obtained in early 2005. Credit: ESO

    Q: By sharing its data, how does ESO benefit?

    A: What ESO gets in return is that more science is done with our data.

    Enabling major scientific discoveries by the astronomical community is core to ESO’s mission. The ESO Science Archive plays a very significant role in this: 30% of the refereed publications that use ESO data make use of archival data. In addition, the Science Archive broadens the user base of ESO data: about 30% of the users of the archive do not use ESO in any other way. And again, open access to data is a staple of research. Astronomy as a discipline and ESO, in particular, have long been pioneers in this area. In order to further increase archive use of the data, we have recently developed the Archive Science Portal to provide more intuitive, enhanced data discovery tools to our users.

    Open access to science data is also a pivotal policy point for governments and funding agencies around the world. Most notably, the European Commission has launched and is shaping the European Open Science Cloud (EOSC). ESO has endorsed the EOSC Declaration in recognition of the vital need for open access to trusted and reliable data in today’s world of scientific research. We also actively collaborate with other observatories and data centres worldwide, most notably with ESA and the Strasbourg astronomical Data Centre (CDS), to foster the open exchange of science data.

    Q: Who uses ESO data?

    A: Scientists are the main users of ESO data. Since 2011, more than 7000 professional astronomers have accessed the ESO Science Archive. For reference, this is between a half and two-thirds of astronomers worldwide, as gauged by the number of IAU members. As mentioned earlier, they use the data in a variety of ways that ultimately lead to more science being done and more knowledge being extracted from the data.

    There are other scientists than astronomers who use the ESO Science Archive, for example, the people who study the Earth atmosphere. In contrast to astronomers, they are not interested in the celestial objects. Rather, they study the composition of the atmosphere above the observatory and how it changes over time, which relates to climate studies. Such cross-disciplinary science is growing in importance.

    There are also amateur astronomers and teachers among the visitors to the ESO archive. Unfortunately, we do not have a good handle of what they do with it. Perhaps it would be worth it trying to learn more about this, as it may be worth experimenting with citizen science.

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    The number of refereed papers published based on data from ESO and other telescopes over the period 1996 to 2017. These numbers are from the ESO Telescope Bibliography (telbib).
    Credit: ESO [There are many astronomical assets simply not included n this portrayal, which mostly serves to benefit ESO.]

    Q: Are there any restrictions — are some data off limits?

    A: The basic policy is that access to data is initially restricted to the scientists who triggered their creation, after which it becomes publicly available.

    Observing with ESO telescopes is a competitive process. Teams of astronomers submit their ideas for new observations to ESO, which organises a peer-review process within the astronomical community itself. The proposals that are approved through this process are executed and generate new data, which is stored in the ESO Science Archive. Access to this data is initially limited to the original proposers of the observations, typically for a period of one year, after which the data itself becomes available without restrictions. The purpose of the policy is to recognise the effort that went into new data being generated while preserving the principle of open data access.

    There are, of course, exceptions to the general policies and they can go both ways. In some cases, most notably with the Public Surveys, raw data is public immediately. Also, the Principal Investigator of such surveys has to return processed data to the archive for the community at large to benefit. The same applies to Principal Investigators of Large Programmes. In both cases, this is in recognition that the large investment of telescope time needed to carry out these large, coordinated observational campaigns has to have a large return for the whole community.

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    This picture of the spiral galaxy NGC 3621 was taken using the Wide Field Imager (WFI) at ESO’s La Silla Observatory in Chile.

    ESO WFI LaSilla 2.2-m MPG/ESO telescope at La Silla, 600 km north of Santiago de Chile at an altitude of 2400 metres

    The data used to make this image were selected from the ESO archive by Joe DePasquale as part of the Hidden Treasures competition.
    Credit: ESO and Joe DePasquale.

    In other cases, at the discretion of the Director General, the proprietary rights can be extended if a valid justification exists. This can be applied to individual observations or groups by extending the proprietary protection period, or even to the knowledge that certain data was acquired in the first place. An example of this is the follow-up with ESO telescopes of gravitational wave signals, in which the potential detections themselves were not immediately made public. In these situations, the fact itself of pointing a telescope in a given patch of the sky would give away confidential information, hence the special treatment.

    Q: Do you expect ESO to continue to make this data widely available in the future, particularly in the era of the ELT?

    A: Most definitely! The science return of doing so is evident, as are the wider cultural implications. Plus, ultimately the data generated by ESO is the result of a large investment of public money and it is only fair that it is accessible for everyone to benefit. The ELT will be a unique science machine that will generate preciously unique data and science opportunities. Open access to this data will be fundamental to fully exploit its amazing potential.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

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    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

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  • richardmitnick 4:25 pm on June 2, 2018 Permalink | Reply
    Tags: , , , , ESA and ESO work closely on NASA/ESA Hubble Space Telescope, ESO also makes ground-based follow-up observations of ESA discoveries, ESO and ESA, ESO and ESA generate a significant fraction of science data from ground and space for the European astronomical community (and beyond!), ESO and ESA share a number of goals and ambitions but it wasn’t until 2015 that we signed a formal cooperation agreement to foster future collaborations on themes of common interest, ESO contributes to the International Asteroid Warning Network (IAWN) which aims to detect track and physically characterise Near-Earth Objects (NEOs), ESO offers VLT observing time to perform critical observations of NEOs that cannot be performed using either ESA telescopes or other small telescopes, ESOblog, Gaia-ESO public spectroscopic survey, The ESA/ESO science working group is driving several new collaborative ventures including joint annual ESA/ESO workshops and a joint ESA/ESO Fellowship programme   

    From ESOblog: “How ESO collaborates with ESA” 

    ESO 50 Large

    From ESOblog

    1
    VLT

    1 June 2018
    Letters from the DG

    In this week’s blog post, ESO Director General Xavier Barcons discusses the close relationship that ESO enjoys with our fellow intergovernmental organisation dealing with space, the European Space Agency. Xavier talks about just a few of the activities that ESO and ESA work on together, and explains how sharing our knowledge and expertise strengthens Europe’s position in our knowledge of the cosmos.

    Greetings to all and welcome back to the ESO blog!

    In my previous blog posts I’ve talked about the work we do internally here at ESO, but in this post I want to take the opportunity to look outward, specifically towards our fruitful and exciting relationship with the European Space Agency (ESA).

    Since ESO was set up in 1962, it has carried out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities that enable important scientific discoveries. Whilst we have been focused on ground-based scientific observations of the Universe here at ESO, ESA has been developing a number of space-related programmes, with space science being one of its many exciting objectives.

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    ESA’s impressive fleet of astronomical spacecraft, many of which share similar scientific aims and technology to ESO’s telescopes. Credit: ESA

    ESO and ESA share a number of goals and ambitions, but it wasn’t until 2015 that we signed a formal cooperation agreement to foster future collaborations on themes of common interest. This agreement provides a framework for a closer collaboration and exchange of information in several areas, including scientific research and technology. Ever since, we have been building our relationship and extending our collaborations more and more each year.

    By working collaboratively we ensure that our Member States (many of which we have in common) are benefitting from the most productive science and the most advanced technologies possible. Our cooperation agreement promotes the coordination of both organisations’ long-term plans, and allows us to work together on specific programmes and share best practices.

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    Representatives from ESO and ESA at the last coordination meeting, held at ESO Headquarters in Germany last January. Credit: ESO

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    The Director Generals of ESO and ESA visit the Very Large Telescope at Paranal Observatory. From left to right: Fernando Comerón (ESO’s Representative in Chile), Fabio Favata (Head of the ESA Programme Coordination Office), Johann-Dietrich Wörner (ESA Director General), Tim de Zeeuw (ESO Director General), Laura Comendador Frutos (ESO ‎Head of Cabinet of the Director General & Head of Legal and International Affairs), and Álvaro Giménez (ESA Director of Science and Robotic Exploration).
    Credit: ESO

    As part of our cooperation agreement, we have created three working groups consisting of members from both ESO and ESA: one in science, one in technology, and one in communications. Every year, these groups come together and their leads report to a meeting with myself and Johann-Dietrich Wörner, the Director General of ESA. During these meetings, we all enjoy hearing about the inspiring projects that the respective working groups collaborate on, and we keep pushing our teams to strengthen the existing joint ventures.

    Science

    ESO and ESA generate a significant fraction of science data from ground and space for the European astronomical community (and beyond!). The ESA/ESO science working group fosters collaboration between the organisations, to ensure that both organisations’ resources are used efficiently, and to explore synergies of science operations for ground and space missions. There are a number of ways in which these aims are achieved successfully.

    Gaia is an ambitious ESA mission that is creating a three-dimensional map of the Milky Way, pinpointing the positions of stars with extraordinary precision; its eagerly-awaited second data set has just been released.

    ESA/GAIA satellite

    ESA and ESO work together closely on the Gaia-ESO public spectroscopic survey, which aims to provide an overview of the motions and chemical compositions of stars in the Milky Way.

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    Map of observed targets on the sky (provided by Cambridge Astronomy Survey Unit (CASU), see Gaia-ESO Survey overview). Observations included in the fifth internal Survey data release (iDR5; from the beginning of the Survey up until December 2015) are shown. Key: MW = Milky Way, CL = Cluster, SD = Standard.

    The results of this survey will revolutionise our knowledge of galactic and stellar evolution. Data obtained using ESO’s Very Large Telescope (VLT) will be combined with data from Gaia to provide a legacy dataset that adds enormous value to the Gaia mission and ongoing ESO imaging surveys. The Gaia satellite is also observed regularly by ESO’s VLT Survey Telescope (VST), in order to measure its location extremely precisely, resulting in an improvement of the astrometric accuracy of the Gaia star catalogue.

    In addition to the Gaia-ESO spectroscopic survey mentioned above, ESO telescopes have devoted substantial amounts of observing time (often through Large Programmes, which utilise hundreds of hours of observations) to support scientific objectives shared with ESA science missions. This scientific cooperation channel will remain open, welcoming proposals to use ESO telescopes by teams exploiting ESA science missions.

    Another hugely successful space mission that ESA and ESO work closely on is the NASA/ESA Hubble Space Telescope. The Space Telescope European Coordinating Facility (ST–ECF) was, until the end of 2010, the European branch of the Hubble science facility. It supported the European astronomy community in exploiting the research opportunities provided by the Hubble Space Telescope. ESA and ESO continue to work closely on the communication of Hubble, which I will discuss later in this post.

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    This detailed view shows the central parts of the nearby active galaxy NGC 1433. The dim blue background image, showing the central dust lanes of this galaxy, comes from the NASA/ESA Hubble Space Telescope. The coloured structures near the centre are from recent ALMA observations that have revealed a spiral shape, as well as an unexpected outflow, for the first time. Credit: ALMA (ESO/NAOJ/NRAO)/NASA/ESA/F. Combes

    ESO also makes ground-based follow-up observations of ESA discoveries. As part of the cooperation agreement, ESO contributes to the International Asteroid Warning Network (IAWN), which aims to detect, track, and physically characterise Near-Earth Objects (NEOs) to determine whether any are potentially dangerous to Earth. The network is made up of scientific institutions, observatories, and a variety of interested groups, all of which can make observations of asteroids and NEOs. As part of this contribution, ESO offers VLT observing time to perform critical observations of NEOs that cannot be performed using either ESA telescopes or other small telescopes. These observations constrain the orbits of faint NEOs newly discovered by ESA, which would be lost without immediate follow-up. The observations also characterise and refine the orbits of faint, known NEOs on threatening orbits. As of July 2017, ESO had made 80 observations of 61 objects. Of these, 21 were removed from the “risk list”, and 20 more have had their risk downgraded. In 6 cases, the improved understanding of their orbit resulted in an increase of their risk.

    The ESA/ESO science working group is driving several new collaborative ventures, including joint annual ESA/ESO workshops and a joint ESA/ESO Fellowship programme. The latter will see the recruitment of a talented postdoctoral researcher to work on a synergetic project — for example, ESA’s PLATO mission.

    ESA/PLATO

    PLATO is an ESA satellite which will look for exoplanets via the shadows cast by their transits across the face of their star, but which will rely on ground-based telescopes for radial velocity measurements to tie down orbital parameters and exoplanet masses.

    Planet transit. NASA/Ames

    Radial velocity Image via SuperWasp http:// http://www.superwasp.org/exoplanets.htm


    Radial Velocity Method-Las Cumbres Observatory

    The Fellow would link ESA and ESO, travelling between the two to share knowledge and experience.

    With the aim of taking full advantage of complementary ground-based and space-borne observing facilities, ESO and ESA jointly support scientific programmes that require observations with both the ESO VLT(I) telescopes and the XMM-Newton X-ray observatory. ESO may award up to 80 hours of XMM-Newton observing time and the XMM-Newton project may award up to 80 hours of ESO VLT(I) observing time to proposals wishing to use both facilities. This collaboration has so far lasted over a decade.

    With the aim of taking full advantage of complementary ground-based and space-borne observing facilities, ESO and ESA jointly support scientific programmes that require observations with both the ESO VLT(I) telescopes and the XMM-Newton X-ray observatory.

    ESA/XMM Newton

    ESO may award up to 80 hours of XMM-Newton observing time and the XMM-Newton project may award up to 80 hours of ESO VLT(I) observing time to proposals wishing to use both facilities. This collaboration has so far lasted over a decade.

    Technology

    But we don’t only share scientific aims. A ground-based telescope in the Atacama Desert has a lot in common with a space-based satellite orbiting the Earth, so both ESO and ESA share a lot of the same technology, including optics, electronics, mechanics, materials. We also use similar software and have similar systems overall. Sharing documentation, research results, knowledge and experience is a highly productive way to work.

    ESO has a lot of expertise in laser guide stars and adaptive optics technology.

    ESO VLT Laser Guide Stars

    ESO 4 laser guide stars on UT 4

    We not only share that expertise with ESA, but we also work with them to develop that expertise even further. Furthermore, we collaborate on the development of ever smoother, bigger, and better mirrors, which are of course used on both ESO and ESA telescopes. We share and develop software together too, including image analysis and production tools. Recently we have begun to collaborate on the development of curved CCD detectors to use for wide and curved focal planes.

    Both ESO and ESA host a wealth of state-of-the-art research facilities, and we take advantage of our close relationship not only to use each other’s facilities, but also to share results and conclusions from our own facilities.

    We will continue to keep the communication channel open with regards to technology research and development, in order to potentially identify further collaboration initiatives.

    Communication

    Both ESO and ESA pride themselves on their public outreach activities, and work together to successfully communicate astronomy, space science and space technology.

    In particular, we work together on communications for the NASA/ESA Hubble Space Telescope. In late 1999, a science communication office was established at the Space Telescope European Coordinating Facility (ST-ECF) to carry out the Hubble communication on behalf of ESA. After ST-ECF’s closure in December 2010, ESO continued the core Hubble communications, an arrangement that remains in place today.

    This year, ESA and ESO plan to hold an internal communication workshop that will cover topics such as audiovisuals, social media, news activities, and exhibition activities. We hope to continue to organise these collaborative workshops in the future in order to share experience. Often, scientific discoveries involve both ESA and ESO; as part of our cooperation agreement, we pay special attention to mentioning each other where possible in the news releases announcing these discoveries, and use such news to develop our relationship further.

    We have worked together on a variety of educational materials, including the ESA/ESO exercises which give students a taste of what it’s like to be an astronomer. We also both worked with the European Organization for Nuclear Research (CERN) on a project called Physics on Stage, which selected new ideas for presentations and educational materials and showcased them at the Physics on Stage Festival.

    In the future, we would like to explore the production of a shared manifesto, aiming for a series of principles and values, and a common vision for science communication in Europe. Such a manifesto would help align communication efforts and position Europe at an intercontinental level.

    Here at ESO, we are extremely proud of our relationship with ESA, but we are also proud to be part of a larger group of scientific organisations — the EIROforum. The EIROforum brings together eight of the largest European research organisations with the aim of sharing the expertise of each member organisation to help European science to reach its full potential.

    The projects I have mentioned in this blog post form only part of the areas that ESA and ESO work together on. Having served in a number of ESA science committees and science missions myself, these collaborations are all very close to my heart. We hope that these close relationships continue to grow for many years to come.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 9:51 am on May 27, 2018 Permalink | Reply
    Tags: , , , , , , ESOblog   

    From ESOblog: “Astronomer Henri Boffin on ESO’s collaboration in the Gaia mission” 

    ESO 50 Large

    From ESOblog

    25 May 2018

    1
    From ESA/GAIA

    ESA/GAIA satellite

    Mapping the sky has been one of humanity’s quests since the dawn of time, and ESA’s Gaia satellite is taking our understanding of our stellar neighbourhood to a whole new level. But it can’t do this alone. ESA has a close collaboration with ESO to use our ground-based expertise to help Gaia excel up in space. We talked to ESO astronomer Henri Boffin to find out more.

    Q: Firstly, could you explain what Gaia is and what kind of data it collects?

    A: Gaia is an astrometric mission from the European Space Agency that has been in the making for decades. It was launched at the end of 2013 and since then it has been using its two telescopes to very precisely measure the position, motion and brightness of more than a billion stars in our galaxy, the Milky Way. At the end of the mission, it will provide us with the most precise 3D map of our galaxy ever made.

    Q: In 2016, ESA released the first data set from Gaia. In April this year, the second data set was released — how does it differ?

    A: In Gaia data release 1, only the positions of most of the objects that Gaia could detect were provided. In data release 2, however, things start to become much more interesting, as Gaia is now providing estimates of the distance, the motion and the brightness for a large subset of stars. The dataset has information on the position and brightness of 1.7 billion stars, the parallax and motion of 1.3 billion stars, the surface temperature of over 100 million stars and the effect of interstellar dust on 87 million stars. Gaia has even given us some information about other objects like asteroids within our Solar System, far-off quasars, globular clusters within our own galaxy and dwarf galaxies orbiting it.


    A virtual journey from our Solar System through our Milky Way, based on data from the first (left) and second (right) release of ESA’s Gaia satellite. The journey starts by looking back at the Sun, moving away and travelling between the stars.
    Credit: ESA/Gaia/DPAC

    Q: Why is this extra information so important to astronomers?

    A: Knowing the distance to a star is a crucial piece of information — without a star’s distance, it is hard to do any astronomy. In fact, one could say that astronomy has always been about tackling the challenges of measuring astronomical distances! If you only see the brightness of a star but don’t know how far away it is, it’s hard to understand what kind of object it is. It’s like when you see a light at night time. It could be someone walking with a small flashlight a few metres away or it could be a lighthouse located tens of kilometres away!

    Once you know the distance to a star, it is possible to know if it is intrinsically bright or faint. You can also determine other properties such as the star’s mass, whether it is still in its infancy or if it will soon explode as a supernova. Distances are also needed to know the size of the Universe, whether it is expanding, and by how much.

    Q: What role does ESO play in the Gaia mission?

    A: ESO has been involved in the Gaia mission in several ways. The first one is the Ground-Based Optical Tracking programme, or GBOT. This involves tracking the position of the Gaia satellite using the 2.4-metre VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile.

    The second major involvement of ESO telescopes is in the Gaia–ESO public spectroscopic survey.

    Moreover, ESO astronomers are interested in using Gaia data not only for their science, but also for operations. For example, it’s planned that the Gaia catalogue will be used as the basis of guide stars for ESO’s Very Large Telescope and Extremely Large Telescope. These telescopes need to use guide stars to precisely track the movement of the sky and keep their desired targets fixed in their field of view.

    Finally, ESO is also co-organising a scientific workshop in September 2018 that will focus on the advances in our understanding of stellar physical processes, made possible by combining the astrometry and photometry of Gaia with data from other large photometric, spectroscopic, and asteroseismic stellar surveys.

    Q: Could you explain further about the Ground-Based Optical Tracking programme?

    A: Gaia is the most accurate astrometric device ever built, but in order for its observations to be useful astronomers analysing the data need to know exactly where it is in the Universe. Its position needs to be known to an accuracy of 150 metres (a challenge given that it is 1.5 million kilometres away) and the velocity needs to be measured with an accuracy of 0.009 km/h!

    The only way to know the velocity and position of the spacecraft with very high precision is to observe it on a daily basis from the ground. But the usual ESA tracking stations are not sufficient for this, so the consortium turned to the VST to track the satellite. So, since the launch of Gaia at the end of 2013, the VST has been taking images of Gaia every other night.

    3
    These images from ESO’s VST show ESA’s Gaia spacecraft in its position some 1.5 million kilometres beyond Earth’s orbit. The VST captured these images using OmegaCAM on 23 January 2014, taken about 6.5 minutes apart. Gaia is clearly visible as a small spot moving against a background of stars. Its location is circled in red. In these images, the spacecraft is about a million times fainter than is detectable by the naked eye.
    Credit: ESO

    ESO OmegaCAM on VST at ESO’s Cerro Paranal observatory,with an elevation of 2,635 metres (8,645 ft) above sea level


    ESO OmegaCAM on VST at ESO’s Cerro Paranal observatory,with an elevation of 2,635 metres (8,645 ft) above sea level

    Q: Why is the VST used instead of other ESA tracking stations?

    A: The ESA tracking stations are radars that rely on measuring the radial velocity of the satellites. They are extremely precise, but only for the motion towards us. In order to obtain the real position of an object in space, one would need to combine observations of two such tracking stations. This is, however, very time consuming — and these tracking stations are required for all the other satellites of ESA as well. So it’s not possible to monopolise them for Gaia.

    The consortium of astronomers in charge of analysing the Gaia data came up with another solution — using a 2-metre class telescope to track the satellite. They mostly use the VST for this, as well as the Liverpool Telescope located on the Canary island of La Palma, Spain.

    2-metre Liverpool Telescope at La Palma in the Canary Islands, Altitude 2,363 m (7,753 ft)

    The VST is particularly suited for this task because it can take images of a very large area of the sky. In fact, as an aside, because of this capability, the VST takes images of dozens of asteroids every time it captures the Gaia satellite! In three years, it has discovered almost 9000 asteroids.

    Q: Tell us more about the Gaia–ESO public spectroscopic survey. What value does it add to the Gaia data?

    A: The Gaia–ESO public spectroscopic survey obtained high-quality spectroscopy of about 100 000 stars in the Milky Way with the FLAMES instrument on the VLT.

    ESO/FLAMES on The VLT. FLAMES is the multi-object, intermediate and high resolution spectrograph of the VLT. Mounted at UT2, FLAMES can access targets over a field of view 25 arcmin in diameter. FLAMES feeds two different spectrograph covering the whole visual spectral range:GIRAFFE and UVES.

    The survey spanned six years and used more than 300 nights of telescope time. These spectra allow astronomers to determine the chemical composition and the radial velocities of the stars. Although Gaia is able to take spectra, it can only do so for the brightest stars and in a very limited spectral range. So there was a need to obtain more precise data for fainter stars, in order to systematically cover all major components of the Milky Way, from the halo to clusters of stars to star-forming regions. When combined with the distances measured by Gaia, the survey will quantify the formation history and evolution of young, mature and ancient galactic populations, providing unprecedented knowledge of the evolution of our galaxy and its stars. This creates a legacy dataset that adds enormous value to the Gaia mission.

    Q: What will the future role of ESO be in relation to the Gaia mission?

    A: ESO will of course continue to track the Gaia satellite for several years, but ESO telescopes will be needed for following up many of the targets that Gaia has found to be particularly interesting (and there will be many!). Gaia should lead to the discovery of thousands of exoplanets, tens of thousands of brown dwarfs, more than 20 000 exploding stars, and countless numbers of variable and binary stars, as well as 500 000 distant quasars. Astronomers will most likely want to study many of these in detail. This will require high-multiplex instruments, so the future MOONS on the VLT and 4MOST on VISTA are going to play an important role. And of course, for many decades to come, astronomers will use the distances provided by Gaia to better understand their favourite objects.

    4
    This conceptual engineering drawing shows MOONS, a unique new instrument for ESO’s Very Large Telescope. MOONS will be able to tackle some of the most compelling astronomical questions such as probing the structure of the Milky Way and tracing how stars and galaxies form and evolve.
    Credit: ESO/MOONS Consortium

    Q: What excites you most about Gaia, and in particular about ESO’s involvement?

    A: The sheer amount of data that comes out of Gaia is truly amazing. To know that we will soon have a full understanding of our own galaxy and the myriad stars it contains is mind-blowing!

    I am rather proud that ESO is playing a role in this by tracking the satellite, but as an astronomer I am also very keen to use the Gaia data. In fact, together with colleagues here at ESO, I am currently finishing a study that relies on Gaia data to analyse the well-known star-forming region of Orion in great detail. When we first saw what we could do with these stars using Gaia, we could hardly believe our eyes. With Gaia, we can clearly distinguish where the youngest stars are located as a function of their age, and thus see the structure of this stellar nursery in 3D.

    Q: When is the next data release and what can we expect it to add to our knowledge?

    A: The third data release should come out at the end of 2020. It will improve on the parameters of the stars, distances and motions, as well as provide a catalogue of all the stars that are part of binary or multiple systems. But astronomers will be keen to wait for the final data release, hopefully around 2022, as it will provide orbits for many binary stars and objects in our Solar System, light curves of many variable stars, and a list of all the exoplanets found. This immense amount of data will create work for at least the next generation of astronomers, and perhaps further generations too.

    See the full article here .


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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VST) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light.
    Credit: ESO/Y. Beletsky

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 6:12 pm on May 4, 2018 Permalink | Reply
    Tags: A Brilliant New Supernova Shines Over Munich, , , , , , ESOblog   

    From ESOblog: “A Brilliant New Supernova Shines Over Munich” 

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    ESOblog

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    Outreach@ESO

    4 May 2018

    The ESO Supernova Planetarium & Visitor Centre opened its doors to the public on 28 April 2018 and one of our writers, Stephen Molyneux, was there to check it out for the first time. The centre is located right next to ESO Headquarters in Garching bei München, Germany, and it’s a full-on astronomical experience complete with a huge exhibition and immersive planetarium shows. Stephen reports on his visit.

    The first thing that strikes me about the ESO Supernova Planetarium & Visitor Centre is the building itself, which is architecturally magnificent. It was designed by the architecture firm Bernhardt + Partner to look like a double star system with one transferring mass to the other. This cosmic event would eventually result in one of the stars exploding as a supernova in a brilliant flash of light — hence the centre’s name.

    Before I have a full look inside I get the chance to chat to Tania Johnston, ESO Supernova coordinator. She tells me that the idea for the centre was first proposed in 2011 and construction started February 2015.

    “It’s fantastic to finally have the Supernova open and I’m really looking forward to seeing the response from members of the public,” she says. “It’s been a lot of hard work from a huge number of people and I am so grateful to each and every one of them. This project couldn’t have happened without the staff and volunteers who have helped to create this amazing facility.”


    This ESOcast Light explores the newly-opened ESO Supernova Planetarium & Visitor Centre.
    Credit: ESO

    Entering the building, I step into a large open space, with Jupiter and Saturn hanging over my head and beautiful astronomical images of galaxies and nebulae surrounding me. I’m also greeted by several smiling faces from members of staff and volunteers. Everyone is super friendly and happy to help, whether it was directing me to the bathroom or explaining more about the centre itself. They all seem to be buzzing with excitement and pride at the opening — they have, after all, worked hard on making this dream a reality.


    Time-lapse of the construction of the ESO Supernova Planetarium & Visitor Centre in Garching near Munich in Germany.
    Credit: Timelapse-Camera operator: Carlos Guirao. Music Intro: Jennifer Athena Galatis. Music timelapse: Johan B. Monell (http://www.johanmonell.com)

    “I’m fascinated by astronomy and science communication,” says intern Calum Turner. “The chance to help out and see behind-the-scenes in a cutting-edge astronomy outreach centre is a great opportunity to get more experience, learn more about outreach, and meet the people who communicate science for a living!”

    Mathias Jäger, coordinator of the content production for the permanent exhibition, tells me that their aim was to create an exciting visitor centre to educate everyone, young or old, about the wonders of the world we live in.

    “Visitors getting in touch with astronomy for the first time will be as satisfied as astronomy lovers who want to expand their knowledge,” he says with confidence. “We also explain the topics in simpler terms for our younger visitors, and convey our educational messages in many different ways: classically via panels, more modern via screens showing videos, interactively with instructive games created by HITS, and also experimentally with hands-on stations.”

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    The public enjoy “Stars” section of the permanent exhibition at the ESO Supernova Planetarium & Visitor Centre. The exhibit includes scale models of famous stars, indicating just how relatively little our Sun is. Credit: ESO/P. Horálek

    The exhibition was designed by Design und Mehr in collaboration with HITS — the Heidelberg Institute for Theoretical Physics — and ESO. The 129 panels are located around the edge of the building, along a gently sloping 255-metre-long path. The path takes you all the way to the top of the building and then back to the bottom again, and you can interact with the exhibitions as you go. They’re beautifully designed and very engaging, with explanations suitable for all ages coupled with incredible images — one of my personal favourite parts of astronomy.

    “The exhibition covers a wide range of topics across modern observational astronomy,” explains Jäger. “From planetary science to stars to exoplanets to the most distant galaxies, including information on the different techniques we use to study these objects. The amount of information and topics we cover is amazing!”

    There are also specific themes dedicated to ESO, covering the organisation’s history, how it is run, and some of its biggest discoveries to date. There’s an impressive section about ESO’s Extremely Large Telescope, currently being built in Chile, which will be the largest optical and infrared telescope in existence.

    My personal favourite exhibit is about exoplanets and the search for life elsewhere in the Universe — I’ve always been fascinated by the thought of life out there from watching various science-fiction TV shows and films, and the exhibits in the ESO Supernova feeds into that fascination. There are also some really cool inclusions like the Atacama Desert selfie station and the virtual reality stations that transport you to Chile, allowing you to look around ESO’s amazing facilities. Even cooler, there are some fun interactives where you can make galaxies collide or play Pong with black holes!

    4
    Learn all about the ESO’s Extremely Large Telescope (ELT) at the ESO Supernova Planetarium & Visitor Centre. The ELT will be “The Worlds Biggest Eye on the Sky” and will be a 39-metre mirror telescope sited on Cerro Armazones in northern Chile, close to ESO’s Paranal Observatory.
    Credit: ESO/P. Horálek.

    Those who created the exhibitions also have their personal favourites.

    “My personal highlights are a real meteorite and an ELT mirror segment you can touch, which is something you wouldn’t normally get the chance to do,” says Jäger. “My favourite hands-on is a station where you can build your own lens telescope. And if you get tired of walking you can take a seat in the relativity bike, which allows you to cycle at almost the speed of light!”

    5
    The Atacama desert is home of ESO’s telescopes. This mock-up in the ESO Supernova Planetarium & Visitor Centre transports you to the Atacama desert and is a great photo opportunity for a selfie! Credit: ESO/P. Horálek.

    Perhaps the most exciting part of the experience for me is the planetarium itself. Located in the centre of the facility, it’s the largest tilted planetarium in Germany, Austria and Switzerland. It presents a wide variety of shows and cultural events, ranging from shows suitable for small children such as A Tour of the Solar System to public talks such as Massive Black Holes and Galaxies and musical performances like Stan Dart — Mare Stellaris. There is also a huge programme of bilingual events already planned for the next three months. Almost all activities, except some in English, are fully booked by now.

    During my visit, I watch From Earth to the Universe and am completely mesmerised. The film is a stunning 30-minute voyage through space and time, starting with our neighbours in the Solar System and zooming all the way out to the vast large scale structure of the Universe. The planetarium is wonderfully designed and I’d personally be happy to sit there all day, especially if I was allowed to watch all the planetarium shows!

    6
    Young filmmaker Theofanis Matsopoulos presents a show inside the planetarium at the ESO Supernova Planetarium & Visitor Centre. Mr Matsopoulos directed From Earth to the Universe, the world’s first free downloadable fulldome planetarium movie. Here Jupiter, our Solar Systems biggest planet, waltzes across the dome. Credit: ESO/P. Horálek.

    Strikingly, the ESO Supernova is the world’s first open-source planetarium — a great step forwards for science communication.

    Head of ESO’s education and Public Outreach Department Lars Lindberg Christensen explains: “All the planetarium shows, exhibition and educational content are available online for other museums and planetariums to download and use for free. The ESO Supernova is not just a boon for Germans but also for people in the other ESO Member States and beyond.”

    At the centre of the facility is also an interesting area dubbed “The Void”, analogous to the void of space. The high glass ceiling of this unique room contains a beautiful display of the constellations of the Southern Hemisphere — a new experience for many visitors.

    7
    This is the spectacular star-roof of the centre, which weighs almost 30 tonnes, consists of glass panels set into a metal framework made of triangular sections — 262 of them, arranged to artistically represent constellations of the southern sky.
    Credit: ESO/P. Horálek

    Its walls are covered with a what is arguably the largest image of the night sky anywhere, again viewed from the Southern Hemisphere. The Void is a great space for special events and functions, with a seating capacity of up to 150, and it will also house temporary exhibitions, such as the Our Place in Space exhibition from 17 May – 2 September 2018.

    8
    The Void is located in the centre of the ESO Supernova Planetarium & Visitor Centre and is a great space for functions and special events. Visitors can look through one of the telescopes placed along the balcony areas at the full wall covered by the Milky Way galaxy. Credit: ESO/P. Horálek

    I explored the exhibits at my own pace, but guests can also hop on one of the many guided tours available — including a tour that takes you into ESO Headquarters next door, where you can take a sneak peek at how such a huge scientific organisation is run.

    According to one tour guide Valentina Schettini, “There are no concepts or formulas to be learnt from a tour. It is more about communicating a sense of wonder and curiosity about our marvellous Universe, especially the human adventure represented by the scientific research.”

    9
    An aerial view of the ESO Headquarters with a completed ESO Supernova Planetarium & Visitor Centre. The star-roof can be seen reflecting the clear blue sky.
    Credit: S. Lowery/ESO

    The guides themselves are all very enthusiastic and love to see the reactions of the visitors, especially to hear questions and to hear from younger visitors.

    “I enjoy it when young people, especially teenagers, ask about the daily life of astronomers and want to know how the research actually works,” says Schettini. “You can tell they’re thinking about their own future and that is super exciting!”

    Wherever you’re from, there’s a good chance that you will find someone who will speak your language.

    “The tours will be presented in German and in English and in fact the entire educational offers provided by the ESO Supernova is bilingual,” explains Schettini. “In addition, for special occasions or particular needs, tours could be offered in other languages.”

    10
    Visitors are seen here enjoying a tour of the exhibition by Mathias Jäger, coordinator of the ESO Supernova’s permanent exhibition.
    Credit: ESO/P. Horálek

    At the end of your visit be sure to check out the ESO gift shop filled with awesome astronomical gifts. It has everything ranging from ESO caps, t-shirts and mugs to posters, postcards, pens and stickers.

    Before I left, I chatted to a few members of the public to get their first thoughts about the facility.

    “My first impression was clearly that the whole thing — the building, exhibition, organisation, and so on — is very professional,” says Barnabás, astronomy enthusiast. “It looks very modern, exactly like something built in the twenty-first century should look like. I’ve just run through the exhibition, but it is probably the best I’ve ever seen on this topic and I will definitely visit again.”

    Another visitor Noemi, a resident of the nearby town Garching, says: “The building is very impressive with its large open spaces and the beautiful architecture. The exhibition is definitely interesting for both astronomers and the public since it answers very popular questions in an easily understandable, but still scientific way. Thumbs up for the beautiful pictures on the walls and the floor, as well as for all the exhibits that you can interact with!”

    A supernova can shine brighter than all of the stars in the Milky Way combined, and the ESO Supernova shines in a similar way. I have no doubt that it will generate enthusiasm and a passion for astronomy with young and old alike.

    See the full article here .

    Please help promote STEM in your local schools.
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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 12:34 pm on April 28, 2018 Permalink | Reply
    Tags: , , , , ESOblog, Suzanna Randall,   

    From ESOblog: Women in STEM “Eyes on the Stars” Suzanna Randall 

    ESO 50 Large

    ESOblog

    1

    27 April 2018
    People@ESO

    Over the last 40 years, 12 German men have journeyed into space — but no German women. The initiative Astronautin wants to change that. The ambitious programme is currently training two competitively-selected candidates with the goal of sending one on a research mission to the International Space Station. One of these incredible women is Suzanna Randall, an ESO astronomer based at our headquarters in Munich, Germany. We chatted to her about this amazing opportunity.

    Q: Tell us a bit about yourself! Where did you grow up? How did you end up at ESO?

    A: I was born in Cologne, in the west of Germany. I grew up there and then I went to university in the UK, at University College London, and then I did my PhD in Montreal, Canada. I’ve actually been at ESO since right after finishing my PhD. I first came here on a fellowship in 2006. I was an ESO Fellow first for three years, then I had an unpaid associate position for one year working for quality control at the Very Large Telescope (VLT) and now I’ve been working with ALMA for eight years, in the ALMA regional centre.

    Q: What’s your role at ALMA?

    A: Well, over the past eight years I’ve been doing very different things. At the moment I’m a so-called “sub-system scientist” for a piece of software that is used to assess the quality of ALMA’s data and to make sure that astronomers around the world get the data they requested from the observatory. I also do shifts as the duty astronomer at the telescope, up on the Chajnantor Plateau in Chile, as well as general responding to user queries and helping them prepare their observations.

    Then (in theory!) 20% of my time is spent doing science. I actually just got a referee report so I’m in a bit of a bad mood — it’s very long, filled with things to review and fix, not what you want to get on a Monday morning! The paper was based on VLT data using FORS, VIMOS and FLAMES. My work is essentially looking at very hot, compact stars and studying the way they pulsate. Recently, I’ve moved to looking at stars in globular clusters, specifically at their atmospheres. We’re trying work out how these stars formed and evolved — basically we don’t know where they came from. It’s a fascinating topic.


    This panoramic view of the Chajnantor Plateau in Chile shows the otherworldly site of the Atacama Large Millimeter/submillimeter Array (ALMA). Astronomers use ALMA to study the Universe at millimetre and submillimetre wavelengths Credit: ESO/B. Tafreshi (twanight.org)

    Q: And now alongside your research, you’re training to be an astronaut. What drove you to apply for the Astronautin program?

    A: For me, there was no question, really. Everyone always asks “why did you apply?” and my answer is “why didn’t you apply?” I’ve always wanted to be an astronaut, that’s been a childhood dream, but I was drawn to the Astronautin programme in particular because I like the fact that it’s inspiring German women and girls to go into areas where there aren’t many women. It just jumped out at me — I happened to see the advert online and I was like “okay, I have to go for this”.

    I also like the fact that it’s a short mission because I do want to keep doing astronomy and research at ESO, but the programme is just a couple of years in total, including the mission and training, and then that would be it. And, of course, the whole time being a role model for girls and women.

    Q: Your training schedule must be hectic. Are you still continuing to work at ESO?

    A: Yes I am — I’m very happy at ESO and luckily they are happy to continue paying me! I have reduced my working hours…I’ve gone down to 50% duties and 20% science, which means in theory 30% of my duties can now be used for the Astronautin programme. This includes both the outreach work, like giving interviews and going to events, and the training as well. I can manage that all for now, but once the training begins full-time I’ll have to take leave of absence for a year or two. But I plan to come back to ESO afterwards because I still want to work as an astronomer here.

    2
    ESO astronomer Suzanna Randall has been selected as a new trainee of the initiative Astronautin, which aims to train the first female German astronaut and send her on a research mission to the International Space Station. The announcement was made at a press conference at ESO Headquarters in Garching, Germany on 16 February 2018. Credit: ESO/M.Zamani

    The other issue that we are facing is that funding is still a bit precarious for the Astronautin programme. Though we’ve received lots of enthusiastic support, the programme isn’t funded by a state-run space agency, so we’re still looking for companies to support us with sponsorship contracts where they get media attention in return for their support. So from that perspective, it’s really great that for now, ESO is continuing to employ me and being really flexible to allow me to train. ESO’s Director General, Xavier Barcons, is extremely supportive and enthusiastic about it, and for now, I have this deal that I can spend a big portion of my working time on the Astronautin programme.

    Q: So what exactly will your training involve?

    A: There are multiple parts to our training. At the moment, as I said, we’re kind of limited by funding, because lots of the more exciting things are quite expensive. But I was lucky enough to do parabolic flights right at the beginning of my training, where I got to experience weightlessness, which was amazing.

    For now, I’m focusing on getting my Private Pilot Licence (PPL), which I’m going to do around Munich. I’m looking for a school right now. I also need to read up loads — everyone thinks it’s all going to be exciting survival training, but actually, a lot of astronaut training is reading up on space exploration and the systems of the International Space Station — all the theory! Plus, I need to learn Russian. I’m planning to learn it by getting some basics here and then going to Russia for periods of a month or two and get intensive language tuition.

    Once we know who we’ll be flying with up to the ISS, we’ll go to either the US or Moscow to train on the actual modules. They have replicas of all the ISS modules and components to do all the safety and practical training on. In total, the basic training is about a year to a year and a half, full-time.

    Q: Aside from your research, what do you do in your spare time?

    A: One thing I really enjoy is paragliding. I actually started paragliding in Chile! When I was an ESO Fellow, as part of my programme I had to spend a certain number of nights at the VLT every year, working as a support astronomer. After one of my shifts back in 2008, I visited Iquique in northern Chile, which is one of the best places in the world for paragliding, and that’s where I learned. I’ve done a lot of paragliding in Chile, because I’m often there for work, as well as of course in the mountains near Munich.

    Q: Will this experience with an extreme sport help in the Astronautin programme?

    A: I think it came in handy in the application process because they were looking for someone who is a little bit adventurous, who is used to taking risks in a calculated way. As part of my training now, I have to get my PPL, so my paragliding experience might come in handy there, but officially a paragliding license is not something that you need to be an astronaut.

    Q: What about your work as an astronomer at ESO — do you think that will help?

    A: Well, astronauts are often people with a scientific background, so my experience in astrophysics was definitely a bonus. I’ve spent a lot of my time at both ESO and other telescopes, working under stress with international teams in a very isolated environment, doing other people’s experiments…that’s definitely going to come in handy on the ISS. I mean, of course, it will be in space rather than at ALMA (even though ALMA is quite close to space anyway!) but it’s a similar kind of work.

    ESO-NRAO-NAOJ ALMA several antennae at night with the Milky Way

    Q: What was it like to meet so many other extraordinary women during the selection process?

    A: It was great! During the first phase of the psychological and cognitive tests, I met half the remaining applicants — 45 women from all areas of science. There were doctors, pilots, physicists, engineers… It was actually amazing to be in a room full of so many women who were highly-qualified and also just really nice and interesting people to get to know. One of the most important qualities of an astronaut is the ability to communicate, meaning that you can’t just be a brilliant scientist who’s stuck in their office and can’t speak to others — that wouldn’t really be that useful in this job.

    So the other applicants were all fantastic, and what I took away from the experience is that this myth of intense female competition is just that — a myth! The environment was really supportive the whole time, and now we have a big network of previous candidates who are always keen to know what’s happening.

    Q: You’ll be competing against meteorologist Insa Thiele-Eich for a single place on a space mission. Are you on good terms with her?

    A: Well it is a competition, but also it’s always done this way: every mission has a prime crew and a backup crew, and each astronaut has a one-to-one backup in case anything happens. The thing with astronauts is that even if you get a cold a few days before the mission, that’s it — you’re out, and your backup flies. The idea is that they’ll train both of us right to the very end, and then at some point several months before the mission, it’ll be decided who is the prime and who is the backup. Then the prime will fly, unless something unexpected happens.

    Insa and I are actually on really good terms. Right now our main mission is one that requires teamwork: to get the mission off the ground and to get funding to make sure that one of us can fly. That’s by far the most important thing right now. I’d much rather see Insa go into space than have the project fail completely due to lack of funding.

    Of course, at some point there will be an element of competition — we both want to be the prime candidate — but we’re friends and are very supportive towards each other. I’m often asking how she’s getting on with getting her pilot’s licence because she’s been on the programme for longer than me, so at the moment she’s a bit ahead.

    4
    ESO astronomer Suzanna Randall (left) with her colleague, 34-year-old meteorologist Insa Thiele-Eich (right). Both are training with the initiative Astronautin, which aims to train the first female German astronaut and send her on a research mission to the International Space Station. Credit: ESO/M.Zamani

    Q: What will you do if you miss out on the spot?

    A: I’m seeing the training as an opportunity. Even if I don’t get to fly it won’t be wasted time. I mean, getting my PPL and doing parabolic flights are cool experiences anyway, whether it goes anywhere or not. Of course I want to be chosen and go up to the ISS, but if not then I’ll have learnt a lot and maybe there’ll also be future opportunities. Once you’ve got the astronaut training, if they’re looking for more astronauts you’ve obviously got an advantage.

    I’m very lucky that I can do this training with essentially zero risk, since ESO have said that even if I take a year off I can still come back.

    Q: What excites you most about being part of the Astronautin programme?

    A: What — apart from the actual flight? Obviously, the “going to space” thing is one of the big attractions! Aside from that, it’s getting to be a role model and having the opportunity to do completely new things that motivates me. For example, next week I’m meant to be giving a motivational speech, which I’ve never done before. I’ve done scientific presentations and even outreach presentations, but the opportunity to interact in that way with the public has been very interesting. Very challenging, but also very exciting.

    Q: Is there anything else you’d like to say to our readers, particularly to young women who are interested in STEM?

    A: I would say: if you want to do something, do it. Even if you think that you can’t, just do it.

    For me, I always wanted to be an astronaut but thought it wasn’t realistic. Everyone always told me: “whatever, you’re never going to be an astronaut”. So my backup was astronomy — I read about the ESO telescopes when I was a kid. Chile was amazingly exotic at that time for me, and I thought, “I want to visit those telescopes” and made plans with my friend to go. I never thought I’d actually end up working at ESO! I mean, I’m from a small town in Germany near Cologne, and I was never that great at school in maths or physics. So I didn’t think I’d ever work for ESO, first of all, and now, potentially becoming an astronaut…I never thought that could be a possibility!

    I guess what I want to say is that even if you think it isn’t possible to make your dreams into a reality, don’t give up — you never know when you’re going to get a lucky break.

    See the full article here .

    Please help promote STEM in your local schools.
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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 9:09 am on April 21, 2018 Permalink | Reply
    Tags: , , , , ESOblog, Making Laser Guide Stars Even Brighter   

    From ESOblog: “Making Laser Guide Stars Even Brighter” 

    ESO 50 Large

    ESOblog

    20 April 2018

    Scheduled for first light in the 2020s, a powerful new class of giant telescopes will study the Universe in more detail than ever before — as long as their adaptive optics systems can sharpen their view. ESO’s Laser Systems group is currently undertaking field tests with a specialised laser at the Observatorio del Roque de los Muchachos, at La Palma on the Canary Islands. One of their goals is to make laser guide stars even brighter for large and extremely large telescopes, such as ESO’s ELT and the Giant Magellan Telescope. To find out more, we spoke to Domenico Bonaccini Calia, a physicist from ESO’s Laser Systems Department with over 20 years of experience.

    1

    Q: Domenico, could you briefly explain why laser guide star systems are important to astronomers?

    A: Laser guide stars are used together with adaptive optics, the technology that helps astronomers to compensate for the atmospheric turbulence that affects the images of ground-based observations. An artificial guide star is produced by shining a powerful laser into the sky and exciting sodium atoms in the mesosphere (about 90 kilometres up in the atmosphere). This “star” acts as a reference point that allows adaptive optics to measure and compensate for the turbulence. This means that instruments can create crisp images of astronomical objects as sharp as if the telescope were in space, which is a tremendous advantage.

    Q: What kinds of laser guide star systems does ESO currently employ on its telescope?

    A: Our most advanced lasers have been the outcome of ESO internal research and development, which went on to be patented and engineered by two of our industrial partners, TOPTICA Photonics and MPB Communications. We’ve worked closely with these two partners over the past years to develop the final, extremely well-engineered, deployable laser, starting from our prototyping work.

    This is, for example, the type of laser system used on the Very Large Telescope’s cutting-edge Unit Telescope 4. The system consists of a specially-designed 22-watt laser, operating at a wavelength of 598 nanometres with an emission linewidth of about 0.000003 nanometres (equivalent to a frequency of 2 MHz). This creates a laser guide star that allows the adaptive optics system to measure the image distortion created by the turbulence of the atmosphere, 1000 times per second. From these measurements, the fast deformable mirror of the adaptive optics system can adjust its shape to correct for the distortions and hence make the images sharper.

    Essentially, these are compact laser guide star units, where small, powerful lasers are combined with a telescope system that launches the beam — and this means that the modular unit can be mounted directly onto an existing telescope, to produce one laser guide star per module.

    ESO VLT Laser Guide Stars


    The 4 Laser Guide Star facility of Yepun, UT4 of ESO’s Very Large Telescope. Four modular units composed of a laser and a launch telescope are installed, each producing one LGS.
    Credit: ESO/G.Hudepohl

    The TOPTICA–MPBC lasers are a great development and are becoming a standard for astronomical observatories — the laser is turn-key, can be remotely operated, and is rugged enough to endure the harsh conditions such as temperature variations and the high altitude in the Atacama Desert in Chile. This is why we have also ordered them for ESO’s future Extremely Large Telescope. We received the prestigious Leibinger Innovation Award for this laser development with industry.

    Q: Tell us about the new laser field tests being conducted by ESO now.

    A: Along with institutes from ESO Member States, we are currently using the 20 watt Continuous Wave laser — which was produced during our development — to test various technologies related to laser guide star systems.

    We are using the ESO Wendelstein Laser Guide Star Unit placed 40 metres from the 4.2-m William Herschel Telescope, at the Observatorio del Roque de los Muchachos, on the island of La Palma in Spain’s Canary Islands.

    6

    The Wendelstein laser was developed at ESO’s laser labs in the years 2005–2009. It uses the same technologies as those licensed later in 2010 to TOPTICA and MPBC for the production of our engineered lasers: it uses a powerful 20 watt yellow beam (operating at 589 nm) to make sodium atoms in the Earth’s mesosphere glow, producing a laser guide star 90 km above ground.


    ING 4 meter William Herschel Telescope at Roque de los Muchachos Observatory on La Palma in the Canary Islands, 2,396 m (7,861 ft)


    View of the William Herschel Telescope (WHT), located at the Roque de los Muchachos Observatory, at an elevation of 2400 metres on the Canary Island of La Palma, Spain. The Wendelstein laser is located in the rectangular container to the left, 40 metres from the WHT. ESO’s laser field tests are done in the areas belonging to the Isaac Newton Group of telescopes (UK, ES, NL), which provide logistic and technical support to the team. Credit: ESO/D.Bonaccini Calia

    These tests will help us see the direction of technological developments needed for future, better laser guide star adaptive optics systems

    The tests we are conducting now are strategic; they will help us see the direction of technological developments needed for future, better laser guide star adaptive optics systems — aimed specifically at the next generation of telescopes and instruments.

    To conduct these tests, an even more powerful 589-nm laser is being built at our labs, in collaboration with industry.

    One of the important goals of our research and development is to find a way to make the laser guide star even brighter. It is a very complex problem, linked with the mesospheric environment, atomic physics and quantum theory. In the past, we’ve done experiments on different parameters of the laser emission, and right now we’re working to experimentally evaluate a method known as “frequency chirping”. Essentially, this means that the laser’s emission frequency is changing repeatedly and periodically, to follow the recoil of the sodium atoms induced by their interaction with the laser.

    From our models of sodium atom interactions, frequency chirping should improve the laser guide star’s brightness by a factor at least 1.5. This means more return photons for the same laser power.

    Q: Can you explain why frequency chirping would increase the brightness?

    A: The short answer is that frequency chirping optimises the number of sodium atoms that are able to interact with the laser photons. This means that the artificial “star” will shine brighter. The technique we want to apply is a modification of the atomic Doppler cooling, used in atomic physics.

    The long answer is a bit more complex and depends on the detailed atomic physics of the sodium layer. Ready for some high-level physics?

    When a sodium atom is hit by our laser beam, it absorbs and re-emits the photons, which causes a “recoil” of the atom. This means that each time it emits a photon toward us on the ground, the atom increases its relative velocity with respect to us. Because of the Doppler effect, its resonant frequencies seen from the ground shift by a tiny amount for each photon emission — 0.000000057 nm (equivalent to about 50 kHz). After a number of absorptions and re-emissions, the laser photons can no longer interact with that atom because the continued recoil has given the atom a resonant wavelength out of the 0.000003 nm laser line emission (about 2 MHz). This is called “spectral hole burning”.

    The sodium atoms that have interacted with the laser have therefore acquired a different velocity. This means these atoms require a slightly different laser line wavelength to be excited again.

    If we change the wavelength of the laser accordingly, we can actually follow the atoms into their next velocity class. Here, more atoms are present that weren’t interacting with the laser before, so the total number of atoms interacting with the laser increases — i.e., the laser guide star becomes brighter. This is a sort of snow-ploughing, varying the laser wavelength and using the atomic recoil, to move the recoiling atoms across different velocity classes and accumulating their number in the process.

    For the mesosphere, we calculate that on average, the atomic collisions will reset the atomic velocities about once every 150–200 microseconds. So we derive that the laser photons wavelength should be varied by up to 0.000231 nm (200 MHz), in a sawtooth manner with a period of 0.142 milliseconds. So we shift (sweep) the laser emission line progressively 7000 times per second, going back and forth in the photons vibration frequencies. These values will have to be verified and optimised experimentally during the tests.

    ESO’s Raman fibre laser feeding the frequency-doubling Second Harmonic Generation unit which produces a 20W laser at 589 nm. The picture refers to the experimental unit developed at ESO and in use at La Palma. The light is used to create an artificial laser guide star at the mesospheric sodium layer, 90 km above the ground.
    Credit: ESO/D.Bonaccini Calia

    After testing in the lab at ESO, we will do sky tests at the La Palma site, where we’ll monitor the return flux — i.e., how bright the laser guide star is — while toggling between chirping and no chirping and exploring the optimal settings (in particular, changing the speed and range of the frequency shift).

    For more in-depth details about how we make the lasers “chirp” in this way, please visit our webpage. It gets fairly technical!

    5
    Laser Guide star field tests at La Palma. Observatorio del Roque de los Muchachos. The 4.2m William Herschel Telescope Canary adaptive optics system was used together with the ESO laser guide star unit, to validate the foreseen ELT laser guide star baseline performance.
    Credit: Obs.de Paris/Lisa Bardou, PhD student

    Q: How will this new technology help us to improve observations, with telescopes from ESO and other institutions?

    A: If we demonstrate that the laser frequency chirping gives us brighter laser guide stars, it could be implemented on new (or retrofitted in existing) lasers for laser guide stars. For the same laser power, we will obtain brighter laser guide stars!


    UT4’s laser beam crosses the majestic southern sky and creates an artificial star at an altitude of 90 km high in the Earth’s mesosphere. The Laser Guide Star is part of the VLT’s adaptive optics system.
    Credit: ESO/Y. Beletsky

    This has benefits for the operation of all laser guide star Adaptive Optics systems existing or being built in the world, giving a stronger reference signal for adaptive optics, allowing operation of the instruments when observing closer to the horizon, or when the mesospheric sodium abundance (which varies) is at its minimum.

    Q: Is there anything else you would like to add?

    A: I thank you for this interview. I very much enjoy the work and the activities at ESO — I am honoured to be involved. I find it exciting to work on a mixture of innovative ideas, coming from the constant progress in photonics technologies, the knowledge of astrophysics instrumentation needs, and the experimental work.

    None of this would have been possible without the dedicated, intelligent work of my colleagues in various departments, the contribution of brilliant students, and the encouraging support and trust of the ESO management across the years, up to today.

    The success of our work at ESO for the adaptive optics community is also due to the collaborative spirit and professional engagement of research groups outside ESO. Among others, the Adaptive Optics groups at Durham University (UK), the Observatoire de Paris (F), the Instituto Astrofisico de Canarias (ES), the Max Planck Institut für Extraterrestrische Physik (D) and the Istituto Nazionale di Astrofisica (I), with the groups at Osservatorio di Roma and at Osservatorio di Arcetri.

    At ESO he worked in the adaptive optics group and in 2000 he has created the Laser Guide Star Systems Department, serving as Head of Department until 2010. He has contributed to two laser guide star facilities now installed on the VLT, and is currently responsible for the laser guide star Systems Research and Development activities at ESO, under the Technology Development program.

    D. Bonaccini Calia has received in 2017 the Optical Society of America Fellow Award, for the contribution to the progress of photonics in astronomical instrumentation.

    HighTech ESO lets you discover the technological achievements of ESO and industry that are driving new astronomy research. Find more blog posts about ESO’s cutting-edge research and technology here on the ESOblog.

    See the full article here .

    Please help promote STEM in your local schools.
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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 1:02 pm on April 14, 2018 Permalink | Reply
    Tags: Anita Zanella, , , , , , ESOblog,   

    From ESOblog: Women in STEM – “A Night in the Life of an Astronomer” Anita Zanella 

    ESO 50 Large

    ESOblog

    1
    Anita Zanella

    When most people picture an astronomer, they imagine a man in glasses peering up at the Universe through the lens of a huge telescope. While this might have been accurate a century ago, the life of a modern astronomer is a far cry from this stereotype. To learn more about what it’s like to spend a night at a telescope, we chatted to ESO Fellow Anita Zanella, who just wrapped up an observing run at ESO’s Very Large Telescope in Chile.

    Q: So Anita, tell us about your research and what you do at ESO.

    ____________________________________________________________
    It’s really amazing to look at these beams of light departing from inside the dome and get lost in the darkness of the night sky.
    ____________________________________________________________

    A: I’m an ESO Fellow who studies distant galaxies, trying to understand how they form and evolve through cosmic time. I’m interested in questions like: how are stars born inside galaxies? Why do some galaxies keep forming stars while others stop? Why are galaxies shaped like they are, and how does it change over time?

    I’m enjoying my time at ESO very much because it allows me to undertake my own research, but also discover so many other sides of astronomy that I did not even imagine: how observations are performed, how an observatory is run, how instruments are conceived of and built, how proposals of observations are evaluated and chosen, and so much more. It also allows me to meet and work with people from very different backgrounds, not just astronomers but also people such as instrument scientists and engineers, which is very enriching and mind-opening.

    Another cool thing is that as part of my fellowship, I have to spend 40 nights at the Paranal Observatory in Chile each year. I’m based at ESO Headquarters in Germany, so it takes a long time to reach Paranal — it’s almost a two-day trip! So I decided to have 14-night shifts, meaning I go to Chile three times a year.

    Glistening against the awesome backdrop of the night sky above ESO_s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT.

    2
    Taken from inside the dome of the fourth Unit Telescope of ESO’s Very Large Telescope (VLT), this spectacular shot captures the VLT’s Laser Guide Star (LGS) in action
    Credit: Y. Beletsky (LCO)/ESO

    Q: What is your daily (or rather, nightly) timetable like?

    A: One of the things I really like about observing is that everything depends on nature — not only when and what to observe, but also the daily schedule of people working at the observatory. Night astronomers work every day, from sunset to sunrise. Two and a half hours before sunset we have a meeting where the daytime crew summarises what work has been done to maintain or repair the telescopes, the status of the various instruments, and what needs to be finished in the remaining hours before sunset. At that meeting, night astronomers specify what instrument they need at the beginning of the night and when they need to start observing.

    So usually I get up in the afternoon a few hours before sunset, grab a quick breakfast, and go to the afternoon meeting. It takes place in the control building, on top of the mountain just below where the telescopes are, but we sleep in the Residencia, a wonderful building, located a couple of kilometres from the telescopes. During the Chilean winter (from June to August) nights are very long, so I travel to the control building by car in about five minutes. But during the Chilean summer (from November to January) nights are short, so I usually get up early enough to have the time to hike to the meeting on the so-called “star track”, a steep path that takes you up to the control building in about 45 minutes. I love walking there, listening to the silence of the desert, watching how the shades and colours change during the day. Sometimes I can also see small animals: a lizard, a bird, some insects…

    After the meeting, we have dinner (or lunch, depending on your perspective!) at the Residencia and drive up to the mountain once again to be in control building a few minutes before sunset. Every time I can, I enjoy looking at the Sun disappearing into the ocean on the horizon, while the sky around becomes orange and pink. It is a show that never ceases to amaze me. And for the first time during my last shift, I also saw the famous green flash: it is not a legend, it’s real!

    Often we have calibrations to make at the beginning of the night. Some of them can be started about half an hour before sunset so the daytime crew takes care of them, while others have to be taken in twilight so the night astronomer is responsible for them. What time the dome first opens depends on the calibrations, but at latest it’s sunset — then the telescopes are ready to observe. Infrared observations can actually be carried out during the evening twilight, as soon as the first stars are visible, and can be used to guide the telescope in order to correct for the rotation of the Earth. Similarly, we can keep observing in the infrared in the morning twilight. But for observations at optical wavelengths, we need full dark so we have to wait for the end of twilight before observing.

    Then half an hour before sunrise, the telescope’s dome has to be closed. The daytime crew arrives at the top of the mountain, where they start their day with a meeting, to check if anything did not function during the night and agree on what needs to be done that day. But at this point, the telescope operators and night astronomers are already in bed!

    Q: Are you working the whole time, or are there times when you’re waiting around?

    A: Often, the observations last for one hour, so while I wait I usually plan what to observe afterwards, or I assess the data taken previously. I’m also always monitoring the current observations, making sure they’re running to plan. In case of bad weather (like if the humidity is above 70% or the wind is stronger than 18 metres per second), we have to close the dome, so I usually just go on with my own research. Of course, from time to time I take a break and go outside to look at the sky with my own eyes: to me, it is always more magical than looking at it through a screen!

    Q: The sky must look amazing without light pollution. Do you also have to keep the observatory dark during the night?

    A: Yes! As soon as sunset is over, blackout blinds are put over the windows in the control room, so artificial light does not pollute the observations. Similarly, blinds cover the windows of the Residencia. From this moment on, astronomers can only use torches if they walk outside, and cars have to keep their lights off. If there is full Moon it is still relatively easy to see the road and even distinguish shapes in the desert, but when the Moon is not there, the darkness is complete. The small artificial lights that help drivers to see the road are really necessary because otherwise the desert is completely swallowed by the night. At that point, the stars above us are the only source of light and it is always amazing for me to stay outside and stare at them.

    Q: Can you leave the control room once you’ve begun your shift?

    A: Well there are always at least two people at each telescope — one night astronomer and one telescope operator — and there are six consoles (or workstations) in the control room at Paranal: four for the UTs, one shared between the two survey telescopes (VST and VISTA), and one for the VLTI. So there are at least twelve people in the control building, plus visiting astronomers and trainees too. The atmosphere is always very pleasant and often funny, chatting and joking.

    Someone always has to stay at the telescope to check that everything is working properly, which means you’ll always find either the telescope operator or the night astronomer sitting in front of the console. From time to time we leave the control building to take a short walk on the platform where the telescopes are to look at the night sky, or to take visitor astronomers back to the Residencia when they have finished their observations, or to have dinner. (Eating is the last worry in Paranal — food is always available at any time of the day and night!)

    Also, sometimes astronomers are required to work on other projects during the day, so they only have to remain at the telescope until 3 am. In this case, they prepare a queue of observations for the rest of the night and the telescope operator is in charge of carrying them out. Telescope operators always have to stay for the full night, as they are the only ones allowed to move the telescopes. They are very precious because they have an incredible knowledge of how to operate telescopes and instruments!


    A 360-degree panorama of the Control Room, inside the control building, at night: when the action takes place
    Credit: ESO

    Q: Do you also get the chance to make observations for your own research?

    A: Usually I make observations for other astronomers who request them through proposals, but I was once able to observe targets for my own research. The experience was much more intense than observing for others, and it was really special to go through the whole process of conceiving an idea, writing it down in a proposal, having it accepted, taking the data at the telescope, and then using them! It was really thrilling to be at the telescope, waiting for the first image to arrive and immediately seeing if it was what I expected!

    _______________________________________________________________
    These telescopes and instruments are so complex and made of so many different pieces that it is very normal that sometimes something goes wrong.
    _______________________________________________________________

    Q: You said that the daytime crew keeps telescopes and instruments running smoothly, but what happens if something goes wrong during the night?

    A: It may happen that during the night something fails! These telescopes and instruments are so complex and made of so many different pieces that it is very normal that sometimes something goes wrong. Actually, I find it a miracle that everything keeps working smoothly almost every night! So, if something goes wrong during the observations, the night astronomer and the telescope operator leave a message for the daytime crew, who usually fix the issues the next day and the observatory is ready to go again by sunset.

    Q: The length of the night changes from summer to winter — does this affect your observations?

    A: I knew that nights in the winter are longer than in the summer, but realising it at the telescope is a whole different experience and I will never forget it! In the summer nights are short and the twilight is long, so of course, we can observe less, but we can sleep longer during the day and I usually also manage to take some time for myself — for example, taking a walk. In the winter it’s the opposite: sometimes nights are so long they become exasperating!

    On one hand, I like them, because I manage to take many observations and I feel that a lot of science is coming out of the observatory. But on the other hand, the available hours of sleep are barely enough to get enough fresh energy for the coming night, and I usually don’t manage to do anything else except observe, sleep, and eat. After 14 nights it gets a bit exhausting — but very satisfying.

    Surprisingly, it’s more difficult for me to adjust to the season change, especially when I come back from the Chilean summer (+30°C) to the German winter (-10°C). My body gets confused and it takes me a week to get used to the cold again. Switching from cold to warm weather is actually way easier for me…but I have to admit that I am a real fan of summertime!

    Q: What is your favourite part of working at Paranal?

    A: There are so many things that I like about Paranal! I always enjoy being amazed by the night sky, as well as by sunsets and sunrises. I also like to hike in the desert, watching how colours and the light change, stopping from time to time to look at the ocean on the horizon. I still find it amazing that we can see water from the top of a mountain, in the middle of the driest desert in the world! I really like to lie outside sometimes, stopping to breathe for a while and just listen to the silence of the desert.

    I like the working environment of Paranal as well: people really cooperate and work together to get this incredible observatory to function every night. They are always available to help and happy to share their knowledge, to teach you and show you around. I like the enthusiasm. It always gives me a lot of energy!

    Finally, I always find observing itself quite thrilling, waiting for the images to appear on the monitor and having the impression that science is flowing through the telescope!

    See the full article here .

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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 1:53 pm on April 9, 2018 Permalink | Reply
    Tags: , , , , , ESOblog, Mapping the Universe in 3D   

    From ESOblog: “Mapping the Universe in 3D” 

    ESO 50 Large

    ESOblog

    ESO’s telescopes are used to study everything from the tiny dust particles spinning around distant suns to the large-scale structure of galaxies. The Very Large Telescope has recently undertaken a massive project called the VIMOS Public Extragalactic Redshift Survey (VIPERS), which catalogued 90 000 galaxies and measured their distribution as it was between five and eight billion years ago. To find out more, we interviewed Luigi Guzzo, Professor of Cosmology at the University of Milano, who led the VIPERS team.

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    The large-scale distribution of galaxies as it was between 5 and 8 billion years ago, unveiled by the nearly 90,000 new galaxy distances mapped by the VIPERS project.
    Some of the first spectra of distant galaxies obtained with VIMOS, where more than 220 galaxies were observed simultaneously. The light from each galaxy passes through the dedicated slit in the mask and produces a spectrum on the detector; each vertical rectangle contains the spectrum of one galaxy that is located several billion light-years away. These spectra allow astronomers to obtain the redshift, a measure of distance, as well as to assess the physical status of the gas and stars in each of these galaxies.
    Credit: ESO

    VIPERS FACTS
    The “VIMOS Public Extragalactic Redshift Survey” (VIPERS) is a completed ESO Large Program that has mapped in detail the spatial distribution of normal galaxies over an unprecedented volume of the z~1 Universe. It used the VIMOS spectrograph at the 8~m Very Large Telescope to measured spectra for more than 90,000 galaxies with red magnitude I(AB) brighter than 22.5 over an overall area of nearly 24 square degrees. At this redshift, VIPERS fills a unique niche in galaxy surveys, optimizing the combination of multi-band accurate photometry (5 bands from the CFHT-LS, plus Galex-NUV and NIR from WIRCAM and other facilities over most of the area) with the multiplexing capability of VIMOS. A robust color-color pre-selection allowed the survey to focus on the 0.5 < z < 1.2 redshift range, yielding an optimal combination of large volume (5 x 107 h-3 Mpc3) and high effective spectroscopic sampling (46% on average). VIPERS has produced a data set that in many respects represents for the first time the equivalent at z~1 of the large surveys of the "local" (z<0.2) Universe built at the beginning of this century (SDSS and 2dFGRS).

    VIPERS scientific investigations are focusing on measurements of large-scale structure and cosmological parameters at an epoch when the Universe was about half its current age. At the same time, the survey is exploring the ensemble properties of galaxies with unprecedented statistical accuracy at these redshifts, providing the natural extension back in time to classical results from the SDSS.

    Q: Why is cosmology so exciting to you?

    A: Ever since I was a kid, nature and the way things work have always fascinated me. This desire to understand how things work, at the deepest level, meant I would eventually become interested in either the very small or the very big. I ended up fascinated by the incredibly big: astronomy, in general, but mainly cosmology, which is related to the origins of everything, to the earliest questions in the Universe. It is connected to where the Universe comes from and how things originated from its homogenous initial state.

    Q: Tell us about the VIPERS project. What was the initial aim?

    A: VIPERS is a redshift survey, meaning we do a very simple thing: measure the distances of many, many galaxies to reconstruct their 3D distribution in a given volume of space. We have a way to reconstruct these distances because the Universe is quite kind to us: it’s expanding, and the apparent speed of expansion (which we see in the spectrum of each galaxy) is directly connected to the galaxy’s distance from us. The more distant galaxies are, the more rapidly they fly away from us, so the light we see from these galaxies is shifted towards the red. Thanks to this property of the Universe, we can get an approximation of their distance.

    VIPERS is the last in a series of deep surveys that began when VIMOS, the spectrograph at ESO’s VLT, was built at the end of the 1990s. VIMOS is very efficient, capable of collecting different spectra for 400–500 objects at the same time.

    Q: How do you measure the redshift of these galaxies?

    A: Essentially you take the light from galaxies or stars and send it through a spectrograph. A spectrograph is just a prism that splits light into colours like a rainbow. It shows you that in the spectra of stars and galaxies there are hydrogen lines, oxygen lines, iron lines, and so on — the same chemical elements that we know on Earth. These emission or absorption lines have a specific position and a specific wavelength, but decades ago astronomer Edwin Hubble and collaborators noticed that when looking at the spectra of other galaxies, the positions of these lines were moved, shifted towards the red. They also noticed that this shift was higher for more distant galaxies — and this is actually how the expansion of the Universe was discovered.

    Q: Why did you choose to catalogue 90 000 galaxies?

    A: Usually astronomers have to make compromises between their grand scientific aims and what the instrument they’re using actually allows them to do. VIMOS is very special in this respect because there is no other spectrograph in the world that allows you to have the same combination of area of the spectrograph and density of objects that you can observe simultaneously. This makes VIMOS ideal to do these surveys in the distant Universe.

    We chose to survey 90 000 galaxies in order to cover a volume comparable to the volumes we observed at the smaller redshifts (that is, nearby), because we wanted to compare the statistics. We wanted to look over as large a volume of space as possible, but we still wanted the galaxies to be close enough together to allow us to see the details of galactic structures. So we compromised at 90 000.

    Q: So what did this survey tell us about the Universe?

    A: We actually learned a lot about Einstein’s theory of general relativity, which is something we thought about when we proposed the VIPERS project. Galaxies tend to move towards regions of higher density, so, in some way, these galactic motions reflect the growth of the structure of the Universe. As time passes this structure keeps condensing, so when you measure the redshift, you are including this little velocity component that actually contains information about the dynamics of the Universe — and you can use it to determine how quickly these structures grow. In other words, it is a way to test the theory of relativity.

    So, if you have modifications of general relativity on a very large scale, these could be “visible” in the way galaxies assemble. One way to explain such modifications is to include them in the equations of general relativity: as what Einstein called the cosmological constant. We don’t yet understand the origin of this constant, and since it is so difficult to understand in terms of theoretical physics, people started thinking that perhaps it’s not the right solution, perhaps you have to modify general relativity at large scales. This was one of the driving ideas for VIPERS. We presented four measurements of the growth of structure, using four different techniques from the same data, which we published over the past year.

    Q: So what were the main conclusions of the survey?

    A: Essentially all of our measurements are consistent with general relativity. With VIPERS we could see how different types of galaxies trace the structure. For example, we discovered that if we used the luminous blue galaxies, then the measurements of this growth rate are more accurate and less biased.

    Unexpectedly, this survey also allowed us to measure cosmic voids — the spaces between large-scale galactic structures. By looking at cosmic voids with VIPERS, we could see the way galaxies flow away from these voids, because voids are underdense regions, so the galactic structures around them tend to squeeze.

    Equally important, I think, were our results on galaxy evolution. These are really outstanding — by combining VIPERS and the existing Sloan Digital Sky Survey data of the local Universe, we could cover 9 billion years of evolution to see how galaxies transform from the early Universe to today.

    We saw how galaxies change their colour over time. Back in the earlier Universe, we saw a fraction of massive blue galaxies (meaning they are young, active, and still forming stars) which are no longer around today. They’ve become red as they grow older, so the number of red massive galaxies grows while the number of blue massive galaxies declines. That’s a very important result.

    What’s really amazing is that even though we observed 90 000 galaxies, VIPERS was only conducted in 440 hours of observing time. The amount of information it produced is incredible.


    The positions in space of the galaxies identified by the VIPERS survey. This “slice” through the Universe shows where the galaxies lie as we look to ever greater distances in space — corresponding to looking further back in time. Data like these allow astronomers to study the evolution of galaxies as a constituent of the Universe, and tell us about how space itself evolves over time.
    Credit: S. Arnouts, N. Malavasi & the VIPERS Collaboration

    Q: Did you learn any new techniques that might be useful for other projects or fields?

    A: Definitely. What we learned about the instrumentation and the data reduction is now going to be used for a big project of the European Space Agency called Euclid, a space telescope with a spectrograph and an imager on board that will be launched in 2021. My team is involved in the spectroscopic part of the project — which is very different and much more complicated to use than VIMOS, but our work on VIPERS with VIMOS will help us when looking at data from Euclid.

    Q: Is there anything left to do on the VIPERS project?

    A: There are a few more papers in preparation, where we look at more specific details, in particular on the galactic evolution side. In terms of cosmology, I think it is basically done — but our dataset is still a great playground for people who want to test new methods, and we hope the sample will be used a lot by other people with smart ideas, who may find something unexpected. That’s the beauty of these large redshift surveys: the discovery space that you open.

    As a final note, I just want to add that the support from the ESO staff to this project has been really great. One of the reasons why the project went well was because they supported us and always responded promptly to our request and questions.

    The VIMOS Public Extragalactic Redshift Survey (VIPERS)⋆An unprecedented view of galaxies and large-scale structure at 0.5 < z < 1.2. Astronomy and Astrophysics

    The VIMOS Public Extragalactic Redshift Survey (VIPERS)Full spectroscopic data and auxiliary information release (PDR-2)⋆ Astronomy and Astrophysics

    Biography Luigi Guzzo

    Luigi Guzzo is Professor of Cosmology at the University of Milano. He is a cosmologist, interested in observing and modelling the large-scale structure of the Universe. Over the past decade he has led the VIMOS Public Extragalactic Redshift Survey (VIPERS) with the ESO VLT and he is now one of the core science coordinators of the ESA mission Euclid, a space telescope to map the dark and luminous Universe, due to launch in 2021. In 2012 he has received an Advanced Grant from the European Research Council (ERC), a five-year financial contribution that sustained the development of new analysis methods and their application to VIPERS and other surveys.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition
    Visit ESO in Social Media-

    Facebook

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    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 3:50 pm on April 1, 2018 Permalink | Reply
    Tags: , , , , ESOblog, Polaris star system, Richard I. Anderson   

    From ESOblog: “Probing Polaris” 

    ESO 50 Large

    ESOblog

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    Science@ESO

    30 March 2018

    While most people have heard of the North Star and may even be able to find it in the night sky at the north celestial pole, it remains the fascinatingly curious subject of many astronomers’ gaze. This week we speak to astronomer and ESO Fellow Richard I. Anderson, who has been carefully studying Polaris and coming to terms with a seemingly insurmountable problem the famous star poses.

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    Richard I. Anderson.

    Q: Tell us about Polaris. Why is it so interesting?

    A: Polaris, also known as the North Star, is too far north to be seen with any of ESO’s telescopes from Chile, but those in the northern hemisphere can easily find it in the sky as the brightest star in the constellation of Ursa Minor (the Little Bear). For a long time, it played a crucial role in human navigation since it always allows those in the northern hemisphere to find north. But most people don’t know just how interesting Polaris truly is. It’s actually a multiple system consisting of three stars: Polaris Aa, which is a Cepheid variable and the subject of my research, and Polaris Ab and Polaris B, which are both main sequence stars much like our Sun. Importantly, it is the Cepheid Polaris Aa that we see with the naked eye (Polaris Ab and B are more than 500 times fainter).

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    This picture shows the constellations of Ursa Major, Ursa Minor and Polaris, plus the portion of sky studied in the All-Wavelength Extended Groth Strip International Survey (AEGIS). Credit: NASA/ESA, The Hubble Heritage Team and A. Riess (STScI).

    Q: What are Cepheid variable stars?

    A: Cepheids are a class of pulsating stars that exhibit periodic changes in brightness, diameter, and temperature. As they grow and shrink, their temperature changes, making the colour of the star vary from yellow to red. The timescale for these variations ranges from a couple of days to a couple of months, and the brightness changes are so significant that they can be detected by eye — as first discovered by the English astronomer John Goodricke in 1784.

    Stars change very slowly (we say “evolve”) over millions to billions of years because they slowly use up the source of energy at their cores. The structure of stars thus changes slowly with time. Some stars — those between 3–10 times our Sun’s mass — can become Classical Cepheid variables later on in their lives, when small perturbations grow larger and larger until the entire star starts to oscillate. Polaris is such a variable star, more specifically a Classical Cepheid.

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    This sequence of images taken with the Hubble Space Telescope chronicles the rhythmic changes in a rare class of variable star (located in the centre of each image) in the spiral galaxy Messier 100. This class of pulsating star is called a Cepheid Variable. This doubles in brightness over a period of 51.3 days. Credit: NASA/ESA Hubble Space Telescope/W. L. Freedman (Observatories of the Carnegie Institution of Washington)

    Q: Why are Cepheid variables like Polaris so important in astrophysics?

    A: Cepheids are extremely important for two main reasons:

    Firstly, they allow us to determine accurate distances to far away galaxies. Cepheids are so-called standard candles: objects whose true brightness we can calculate based on their period (the time it takes for a star to go from bright to dim). We calculate this through a relationship called Leavitt’s Law. Comparing the true brightness with how bright a Cepheid appears in the sky means astronomers can figure out how far away the star and its host galaxy are — similar to a candle that appears dimmer the farther away it is. This is crucial in cosmology, forming the basis of the cosmic distance ladder that we use to measure how fast the Universe is currently expanding. Not surprisingly, Cepheids are the subject of much research in order to achieve the most accurate measurement of the Hubble constant and to learn about the elusive dark energy.

    Cepheids are also important because their light variations provide insights into the internal structure of stars in an advanced stage of stellar evolution. Understanding how stars evolve is extremely important to all of astrophysics, helping us understand how galaxies evolve, how the building blocks of life came about (since oxygen, nitrogen, and carbon are created inside stars), and many other subjects. Theoretical models are needed to learn about these things. Such models provide very different predictions for evolved stars depending on the assumptions we put into them — we don’t understand them as well as we understand younger stars. These evolved stars are therefore sensitive laboratories for astronomers to learn about stellar evolution.

    For example, an important question in stellar astrophysics is how the rotation of a star around its own axis affects its evolution. Theory predicts that rotation should mix the outer layers of stars in a certain way, and the results of this mixing will show more clearly in the later stages of evolution — such as when stars become Cepheids. This means that rotation can change the surface composition of stars over time. For example, a high ratio of nitrogen to carbon and oxygen is like a smoking gun for stellar rotation.

    Incredibly, in Cepheids we can see stellar evolution taking place on human timescales because we can observe slow changes in the duration of their light variations! This allows us to pinpoint the phase of stellar evolution a Cepheid currently is in. Measuring the chemical composition of a Cepheid’s surface can therefore tell us a lot about how stars evolve in general, and how rotation affects their evolution.

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    Observing Cepheid variables can help astronomers determine relatively short distances in the Universe. Such distance measurements help astronomers calculate how fast the universe expands with time, called the Hubble constant. Credit: NASA, ESA, A. Feild (STScI), and A. Riess (STScI/JHU).

    Q: Why is Polaris Aa a particularly interesting Cepheid to study?

    A: One reason is the uncertainty about its distance — the distance to Polaris has been revised repeatedly by researchers. A recent measurement by Bond et al [The Astophysical Journal]. using the NASA/ESA Hubble Space Telescope placed Polaris at the greatest distance yet, at about 520 light-years away. Remember that Polaris is a multiple star system — and yet the new distance measurement by Hubble was actually based only on observations of Polaris B. The Cepheid, Polaris Aa, would simply have been too bright for Hubble to observe.

    Polaris Aa is also interesting because of its peculiar behaviour, including changes in the size and duration of its light variations — these have puzzled astronomers for a long time. Additionally, given the controversy of its distance in the past, we hadn’t been able to really figure out its evolutionary stage and other properties. Mind you, this is the closest Cepheid from Earth, so we naturally want to be able to understand it.

    What particularly fascinates me is that when this new distance for Polaris B is assumed to be true for Polaris Aa as well, we arrive at an interesting conundrum.

    5
    This sequence of images shows that the North Star, Polaris, is really a triple star system. Credit: NASA, ESA, N. Evans (Harvard-Smithsonian CfA), and H. Bond (STScI).

    A: In my paper, I show that we can finally understand the properties and evolutionary stage of Polaris Aa in unprecedented detail if we use the distance to Polaris B as its distance. The two are very close in the sky and seem to be moving together, so it’s been commonly assumed that the two stars are genuinely at the same distance, gravitationally bound to each other. Moreover, the extremely detailed agreement between theoretical predictions and several independent, highly sensitive observational results shown in my paper renders this assumption a virtual certainty.

    But if the two stars are indeed gravitationally bound, then they should have been born at the same time. This leads to an insurmountable problem: the Cepheid Polaris Aa must be a young star about 50 million years old, whereas B is a relatively old star at two billion years old. This raises very big questions about how these two very differently-aged stars came to be such intertwined companions.

    My paper gives some suggestions for the causes of this age discrepancy, but I haven’t yet found a resolution. For this reason, I have jokingly referred to this case as the “Polaris Uncertainty Principle”: the better you reproduce the properties of the North Star from theory, the less you understand why you managed to do it!

    This is an artist’s impression showing a view from within the Polaris triple star system.
    Credit: NASA, ESA, G. Bacon (STScI)

    Q: So how did you arrive at these results?

    7
    This is an artist’s impression showing a view from within the Polaris triple star system. Credit: NASA, ESA, G. Bacon (STScI).

    A: This age problem has been noted before, but I’ve now confirmed it by comparing observations of Polaris with the Geneva stellar evolution models, which make predictions about stellar evolution that incorporate the effects of a star’s rotation. All stars rotate and yet many researchers still use models that leave out this crucial effect because modelling rotation is difficult and involves a lot of unknowns. I’ve been very interested in using Cepheid variables to test these theoretical models and see where they fail.

    I compared theoretical predictions from Geneva stellar evolution models to observations previously made of Polaris Aa. The results show incredibly detailed agreement between the two, including the rate of period change, Leavitt’s law, Polaris Aa’s colour and brightness, its radius, the abundance of nitrogen in its surface compared to carbon and oxygen, and its mass. Such detailed agreement is very rare for any evolved star, and it strongly supports the assumption that Polaris Aa and B really are at the same distance.

    When I suddenly realised that the Geneva models provided a very consistent picture of the evolutionary status of Polaris, bypassing some of the difficulties encountered by other authors, I was extremely surprised and excited. The best part was that the model predictions that specifically depend on rotation almost exactly matched the observed values! This was a huge success for the models.

    Q: What else was exciting about this research?

    A: On one hand it was the speed with which things happened. I began this work on 22 December last year in response to the paper by Bond et al. mentioned above, and by that same evening, I knew that it was worth writing a follow-up paper of my own. After discussing the result with colleagues at ESO when we returned from Christmas break, I was ready to submit before the end of the first week of January.

    On the other hand, there is this interesting juxtaposition: we had arrived at an incredibly detailed understanding of such an important star, and yet how Polaris B and Aa came to be companions is still a puzzle. This pair cannot be explained using standard stellar evolution theory, and not even by a merger in a binary system!

    Another nice element is that I have been looking at this star since I was a child, observing it with the naked eye from my bedroom window. And now all of a sudden, I know so much about this object. To me, that is the true wonder of astronomy: making sense of the things that are so far out of our reach and yet we nonetheless relate to them at a very basic level.

    Q: What’s next? How might we understand how Polaris B and Aa came together?

    A: A promising route is to simulate how star clusters and multiple star systems evolve together, taking into account the dynamics of their gravitational interactions. If the Polaris system is the remaining core of a star cluster that has since dispersed because of dynamical interactions, then it might be possible to explain the age discrepancy between Polaris Aa and B via such interactions and stars that may have merged. I’ve recently initiated a new collaboration with researchers from Bonn to better understand this dynamical picture.

    Q: How does this result fit into the big picture of your research area?

    A: My research aims to address two fundamental questions of astrophysics: Understanding how rotation affects the evolution of stars and enabling a highly accurate measurement of the expansion rate of the Universe (the Hubble constant).

    With this result, I’ve shown the exceptional agreement between stellar evolution models that include the effects of rotation and Polaris, a star that has long thwarted a detailed explanation. One of the key pieces of evidence for rotation — the abundances of nitrogen, carbon and oxygen in the stellar surface — was spot-on. This is a big success for these stellar evolution models, and I plan to keep testing these models with observational data.

    I’m also currently working on larger numbers of Cepheids that are used to calibrate the cosmic distance scale. Specifically, I work on the effects that companion stars and star clusters have on the calibration of the Leavitt’s law. Understanding these effects — and correcting for them — will be an important step for measuring the Hubble constant with the accuracy required to better understand dark energy.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition
    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 12:28 pm on March 24, 2018 Permalink | Reply
    Tags: , , , , ESOblog, Shooting for the Stars   

    From ESOblog: “Shooting for the Stars” 

    ESO 50 Large

    ESOblog

    1
    Science Snapshots

    23 March 2018

    ESO’s role in the revolutionary Breakthrough Initiatives.

    Our fragile blue planet circles a star that is just one of hundreds of billions in our galaxy — which itself is just one stellar neighbourhood in a vast Universe of at least a hundred billion more. Astronomers, science fiction writers and the public alike have all long wondered: Are we alone in the cosmos? ESO recently joined the search for habitable worlds around other stars in collaboration with the Breakthrough Initiatives, a large-scale science programme to search for extraterrestrial intelligence. We chatted to Markus Kasper, ESO exoplanet expert, to learn more.

    Q: Markus, how did you come to be involved in the Breakthrough Initiatives?

    A: The Breakthrough Initiatives are a suite of scientific and technological programmes dedicated to probing the questions of life in the Universe. In 2015, back before ESO was officially involved, I was invited to join the committee of one of these programmes: Breakthrough Watch (BTW). The objective of BTW is to look for ways to find habitable exoplanets within a five parsec (16 light-year) search radius from Earth.

    To me, this is the most interesting science goal in modern astronomy, because these planets will be sufficiently nearby for the Breakthrough Starshot probes to get there on a reasonable timescale. Breakthrough Starshot is another branch of the initiatives, which aims to design and build ultra-fast, light-driven nano-spacecraft to send to the Alpha Centauri system. This is the closest star system to Earth at just four light-years away, consisting of the binary stars Alpha Centauri A and B, plus Proxima Centauri. But we need to find habitable planets in this system first!

    Q: Why are the Breakthrough Initiatives happening now? Why is this the right moment?

    A: Recent years have brought a wealth of exciting exoplanet discoveries, and we now know that the presence of rocky planets in the habitable zone of a star is the rule rather than an exception. For example, ESO instruments have very recently discovered potentially habitable planets orbiting some of our nearest neighbours like Proxima Centauri and Ross 128. With the emerging class of extremely large telescopes currently under construction, the detection of biosignatures in the atmospheres of nearby exoplanets — gases like oxygen or methane that might indicate past or present life — will be within reach during the next decade, so now is the perfect time to find these exciting planets.

    3
    This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image. Credit: ESO/M. Kornmesser

    Q: Tell us more about how Breakthrough Watch will achieve its goals.

    A: A big problem in exoplanet discovery is that stars are incredibly bright in comparison to their planets, and so habitable planets are hard to detect. But at mid-infrared wavelengths, between 10 and 20 microns, habitable planets become much brighter and are easier to find — between 10 and 12.5 microns, the Earth is actually the brightest planet in the Solar System.

    During the initial meetings of the BTW committee, we identified thermal imaging with 8-metre ground-based telescopes — such as ESO’s Very Large Telescope — as one of the best short-term opportunities to search for Earth-sized, rocky planets in the Alpha Centauri system. In 2016 ESO signed an agreement with Breakthrough Initiatives to follow through with this plan. Agreements for similar efforts with other large observatories (such as Gemini and Magellan) are being considered as well.

    ESO’s goal with NEAR (New Earths in the Alpha cen Region) is to improve the contrast and sensitivity of the existing Very Large Telescope instrument VISIR (VLT Imager and Spectrometer for mid-Infrared) at ESO’s Paranal Observatory in Chile. The proximity of Alpha Centauri means that we could detect of a habitable planet in just 100 hours of observing time on the VLT.

    4
    Every day, before the observations start, each telescope of the VLT undergoes a complete start-up during which each of its function is checked, like a plane before take off. Here, VISIR is visible at the Cassegrain focus of UT3. Credit: ESO

    Q: What technology is being developed to make these observations?

    A: There are three main areas of technological innovation in the NEAR project. Firstly, Adaptive Optics (AO) will be used to improve the point source sensitivity of VISIR. The AO will be implemented by ESO, building on the newly-available deformable secondary mirror at the VLT’s Unit Telescope 4 (UT4).

    ESO/VISIR

    Secondly, a team led by the University of Liège (Belgium), Uppsala University (Sweden) and Caltech (USA) will develop a novel vortex coronagraph to provide a very high imaging contrast at small angular separations. This is necessary because even when we look at a star system in the mid-infrared, the star itself is still millions of times brighter than the planets we want to detect, so we need a dedicated technique to reduce the star’s light. A coronagraph can achieve this.

    Finally, a module containing the wavefront sensor and a new internal chopping device for detector calibration will be built by our contractor Kampf Telescope Optics in Munich.

    6
    This image shows the closest stellar system to the Sun: the bright double star Alpha Centauri AB and its faint companion Proxima Centauri.
    Credit: ESO/B. Tafreshi (twanight.org)/Digitized Sky Survey 2 Acknowledgement: Davide De Martin/Mahdi Zamani

    7
    Glistening against the awesome backdrop of the night sky above ESO’s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 (UT4) of the VLT.
    Credit: ESO/F. Kamphues

    Q: What challenges do you expect to face?

    A: Generally, moving an instrument to a different telescope (in this case, we are moving VISIR from UT3 to UT4) is never a small task, especially for the operations staff at the observatory. An additional challenge is that we have to make NEAR work at its best with a fixed deadline and with sparse resources. The performance goals are very demanding and require one part in a million contrast at less than one arcsecond separation — which is a challenge similar to detecting a firefly sitting on a lighthouse lamp from a few hundred kilometres away! This has not yet been demonstrated in the thermal infrared.

    Q: How long will these first big developments take?

    A: The testing of the hardware in Europe is taking place now, during the first half of 2018. It will be implemented in VISIR at Paranal by end of 2018. The Alpha Centauri observing campaign is scheduled for mid-2019 and will last for about two weeks to collect the required 100 hours of observation time, once the system is delivering the expected performance.

    Q: What exactly is your role in the project?

    A: The work on NEAR is carried out by a small and highly motivated core team at ESO, in collaboration with engineers and scientists from various institutions and countries who are part of the ESO community, as well as industrial partners. My personal role, besides making the link to the Breakthrough Initiatives as a representative, is quite diverse. I mostly work on the design and analysis of the instrumental modifications, but I also develop the concepts for optimum observing and exploitation of the campaign data.

    Q: For you, what is the most exciting aspect of this endeavour?

    A: Besides the fascinating science goals, it is exciting to see how the Breakthrough Initiatives are managing to create momentum in the research field. By backing ideas and projects with a higher risk level than public funding agencies are ready to support, the Initiatives have motivated scientists to push the envelope and leap forward in their research. The Breakthrough Listen branch, for example, searches the sky for radio and laser signals emitted by intelligent beings over a volume in space that is orders of magnitudes larger than what has previously been observed.

    __________________________________________________
    By backing high-risk ideas and projects, the Initiatives have motivated scientists to push the envelope and leap forward in their research
    __________________________________________________

    Q: What hopes do you have for the outcomes of the Breakthrough Initiatives?

    A: I am quite optimistic that we’ll achieve our technical and sensitivity goals with NEAR. Of course, we do not know whether the planets we are looking for actually exist in the Alpha Centauri system. The fact that Alpha Centauri A and B are a relatively close binary may make it more difficult for planets to have formed and exist in the system. The chances are hard to quantify, but if we detected a habitable planet in the Alpha Centauri system it would have incredible impacts even beyond astronomical science — which makes it worth looking anyway.

    And identifying such planets isn’t even the biggest challenge on the cards. Once we know what’s out there, Breakthrough Starshot will aim for in-situ exploration of these systems using microsatellites, which is a whole new technological ball game!

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition
    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
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