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  • richardmitnick 1:55 pm on April 22, 2019 Permalink | Reply
    Tags: , , , , ESOblog, , The Black Hole of Messier 87   

    From ESOblog: “Behind the black hole Messier 87” 

    ESO 50 Large

    From ESOblog

    The first image of a black hole, Messier 87 Credit Event Horizon Telescope Collaboration, via NSF 4.10.19

    Imaging a black hole is no easy task. The Event Horizon Telescope (EHT) project involved over 200 scientists from around the world, and without their hard work, dedication, and imagination, such a feat would never have been possible. Three of these scientists talk about how it feels to be part of an international collaboration that has recently turned the seemingly-impossible into a reality.


    Sera Markoff is a member of the EHT Science Council, co-coordinator of the Multiwavelength Working Group, co-coordinator of Proposals Working Group and leads a research group that contributed to theoretical modelling and interpretation.
    Credit: ESO/BlackHoleCam /Radboud University/ Cristian Afker/Cafker Productions. Produced by: Cristian Afker/Cafker Productions /ESO.

    Name: Sera Markoff
    Job: Professor of Theoretical High Energy Astrophysics, University of Amsterdam, the Netherlands
    Roles in the EHT project: Member of the Science Council, co-coordinator of the Multiwavelength Working Group, co-coordinator of Proposals Working Group and leads a research group that contributed to theoretical modelling and interpretation.

    What has been the most exciting part of this project so far?

    Without a doubt, the most exciting part of the project so far was to make the big discovery — to show the world that black holes really exist, and to quite literally be able to gaze down into that sinkhole. I have been working on modeling black holes in one way or another for most of my career, and I think that one gets a bit blasé at some point, since we use the concept of black holes all the time without having ever actually seen one directly. To really “look it in the eye” is fascinating but also a bit maddening! And now I dream of seeing what it looks like close up, without the distortions of a telescope in between! I want to understand how such a thing can be possible, when our understanding of physics at the moment is not complete and cannot yet explain gravity or black holes at a quantum level.

    I also found working with a big team focused on a single, major goal very exciting. There were so many researchers, particularly PhD and postdoctoral students who dedicated a huge amount of time to making this project a success, and I am very happy to see it pay off for them, since it will boost their careers massively.


    Heino Falcke, of Radboud University in the Netherlands, coined the term “black hole shadow” and was the scientists that originally came up with the idea of imaging a black hole using millimetre-wavelength Very Large Baseline Interferometry (VLBI). Heino is currently chair of the EHT science council and co-Principal Investigator of the European Research Council Synergy Grant BlackHoleCam that co-funded the EHT.
    Credit: ESO/BlackHoleCam /Radboud University/ Cristian Afker/Cafker Productions. Produced by: Cristian Afker/Cafker Productions /ESO.

    Name: Heino Falcke
    Job: Professor of Astroparticle Physics and Radio Astronomy, Radboud University, the Netherlands
    Roles in the EHT project: Coiner of the term “black hole shadow” and proposer to try to image a black hole using millimetre-wavelength Very Large Baseline Interferometry (VLBI). Chair of the EHT science council and co-Principal Investigator (together with Luciano Rezzolla and Michael Kramer) of the European Research Council Synergy Grant BlackHoleCam that co-funded the EHT.

    How did it feel when you saw the first image of the black hole?

    Twenty-five years ago, back in the pioneering days of millimetre-wavelength VLBI, I was doing my PhD at the Max-Planck Institute in Bonn. Modeling the black hole at the centre of the Milky Way, I realised that light of millimetre-wavelength or below would be emitted from close to the black hole’s event horizon. Alas, black holes are surprisingly tiny, so the event horizon seemed too small to see, even with an Earth-sized telescope.

    But then, one lonely afternoon in the library, I stumbled across an article that described how a black hole would look much bigger when illuminated from behind. I was electrified. I hadn’t considered gravitational lensing — that a black hole could actually magnify itself due to the bending of light by its own mass. This would make it look much bigger!

    I worked with two other scientists, Eric Agol and Fulvio Melia, to calculate what a black hole would look like if it was engulfed by a glowing transparent region and, lo and behold, we found that a dark area would appear, surrounded by a bright ring that would be just large enough to be detected. We called the dark area the “shadow of the black hole” and claimed it could be detected within the following ten years!

    Well, not quite. But 19 years later my own PhD student, Sara Issaoun, showed me the first raw data from the EHT project. The plot was a complicated and incomplete one-dimensional mathematical transformation of an image. But doing the mathematical inversion in my head, as we have all learned to do during this project, my heart started beating faster: this could be a ring!

    Weeks later, we could finally make the actual image and there it was — the shadow inside a ring. All these years after predicting that it would be possible to image a black hole in this way, this huge collaboration of scientists had finally done so! For an hour I felt like I was hovering above the ground, but then it hit me that we still had many rough months to go before we could be certain. I sent up a brief “thank you” prayer to heaven and continued the day with a smile on my face.


    Sara Issaoun, of Radboud University in the Netherlands observed using one of the eight EHT telescopes, the Submillimeter Telescope (SMT). Sara also contributed to data processing and calibration, as well as the imaging efforts.
    Credit: ESO/BlackHoleCam /Radboud University/ Cristian Afker/Cafker Productions. Produced by: Cristian Afker/Cafker Productions /ESO.

    Name: Sara Issaoun
    Job: Graduate student at Radboud University, the Netherlands
    Roles in EHT project: EHT observing staff at the Submillimeter Telescope (SMT), core contributor in EHT data processing and calibration, active contributor in imaging efforts

    Describe some of the emotions you went through whilst getting to this result.

    Although I’ve gone through many emotions during this project, the most common is probably exhaustion! During our 2017 observing campaign at the SMT in Arizona, I was excited to be carrying out observations, hearing the equipment roar as blinking green lights indicated the successful collection of data. And the weather was excellent, meaning that we could observe on multiple days in a row. The downside to this? Back-to-back 16 hour observing shifts, with preparation time in between, and very, very little sleep. Combined with the high altitude, this made it an exhausting expedition. But then I saw the messages rolling in from Chile, the South Pole, Spain, Mexico and Hawaii, which made me feel part of a truly historic moment; all these telescopes and people, all staring towards the centre of Messier 87 — just one galaxy in amongst several trillion that exist in the Universe.

    After we packed up our recordings and drove down the mountain, it took a few months before we got the results of our observations. But when we heard that the telescope had worked well, and that we had worked well, I felt extreme relief.

    But it also meant that our data was ready for calibration, which involved a lot more hard work, exhaustion and stress. I will never forget the day when I first saw the fully calibrated data; the quality was so high that it took only seconds for me to understand that this could lead to a groundbreaking image. Four imaging teams worked separately to create the final image, and I was part of one of these teams.

    A mere few minutes after I started processing the data, I saw the ring structure appear. It was jaw-dropping, even thrilling. Six weeks of hard work passed, during which we perfected our image and improved our understanding of the data, before all the imaging teams met at a workshop in July 2018. We were all extremely anxious to see if everyone had seen the same structure. Once again, it turned out that everyone saw the same thing, even though we had all been using different software. This was real. This was it. The room filled with applause and laughter and general awe at being part of this incredible project. We were fully aware of the huge amount of work ahead of us, to understand what we were seeing and convince the rest of the community, but that moment was really special.

    See the full article here .


    Katie Bouman “Imaging a Black Hole with the Event Horizon Telescope”

    Event Horizon Telescope Array

    Arizona Radio Observatory
    Arizona Radio Observatory/Submillimeter-wave Astronomy (ARO/SMT)

    ESO/APEX
    Atacama Pathfinder EXperiment

    CARMA Array no longer in service
    Combined Array for Research in Millimeter-wave Astronomy (CARMA)

    Atacama Submillimeter Telescope Experiment (ASTE)
    Atacama Submillimeter Telescope Experiment (ASTE)

    Caltech Submillimeter Observatory
    Caltech Submillimeter Observatory (CSO)

    IRAM 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada,, Altitude 2,850 m (9,350 ft)


    Institut de Radioastronomie Millimetrique (IRAM) 30m

    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA
    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA

    Large Millimeter Telescope Alfonso Serrano
    Large Millimeter Telescope Alfonso Serrano

    CfA Submillimeter Array Mauna Kea, Hawaii, USA, Altitude 4,080 m (13,390 ft)

    Submillimeter Array Hawaii SAO

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array, Chile

    South Pole Telescope SPTPOL
    South Pole Telescope SPTPOL

    NSF CfA Greenland telescope

    Future Array/Telescopes

    Future Array/Telescopes

    IRAM NOEMA in the French Alps on the wide and isolated Plateau de Bure at an elevation of 2550 meters, the telescope currently consists of ten antennas, each 15 meters in diameter.interferometer, Located in the French Alpes on the wide and isolated Plateau de Bure at an elevation of 2550 meters

    NSF CfA Greenland telescope

    NSF CfA Greenland telescope


    Greenland Telescope

    ARO 12m Radio Telescope, Kitt Peak National Observatory, Arizona, USA, Altitude 1,914 m (6,280 ft)


    ARO 12m Radio Telescope


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

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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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,


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

    ESO VLT 4 lasers on Yepun


    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.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 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 11:54 am on April 12, 2019 Permalink | Reply
    Tags: , , , , , ESOblog,   

    From ESOblog: “Photographing a black hole” 

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    From ESOblog

    Messier 87 supermassive black hole from the EHT

    10 April 2019

    Today, the Event Horizon Telescope team announced that they have “imaged” a black hole for the first time ever. The black hole lies 55 million light-years away at the centre of the massive galaxy Messier 87. Such an incredible feat has taken decades of collaboration between people and telescopes around the world — requiring patience, persistence and perseverance. And the story doesn’t end here. Rubén Herrero-Illana and Hugo Messias, two ESO/ALMA fellows, tell us about how they were involved at the front line of this endeavour, and about the enormous efforts involved in such an astonishing achievement.

    Q. Firstly, could you tell us a bit more about the Event Horizon Telescope?

    Rubén Herrero-Illana (RHI): The Event Horizon Telescope — or EHT — is an experiment that uses eight telescopes around the world to observe some of the closest supermassive black holes with an unprecedented resolution. The scientific goal of the EHT is to find out what happens in the extreme environments around supermassive black holes, which are some of the most intriguing objects in the Universe.

    The EHT uses a technique called very long baseline interferometry (VLBI), in which we make several radio telescopes, separated by thousands of kilometres, observe the same object in the sky simultaneously. By combining the signals from each telescope in a particular way, we are able to mimic a telescope as large as the Earth. To explain just how amazing this is — the resolution that we obtain this way would allow us to stand in Chile and see through the eye of a needle in Spain!

    The participating stations in the EHT include ESO’s APEX telescope and ALMA, which ESO is a partner in.

    3
    Consisting of 66 antennas, ALMA is revolutionising the way that we see the Universe. As well as helping to image black holes, ALMA gives astronomers an unprecedented capability to study the cool Universe — molecular gas and dust as well as the relic radiation of the Big Bang. ALMA studies the building blocks of stars, planetary systems, galaxies, and life itself. Credit: ESO/S. Guisard (www.eso.org/~sguisard)

    Q. What were your roles in the project?

    RHI: For the last two years, we have been involved in the preparation and execution of the observations at ALMA. This involves actually observing on site using the telescope. We have also been part of the group that calibrates the ALMA data and checks their quality before sending them to the correlators, which are the supercomputers th combine the signals from every station.

    Q. What do you mean by ‘calibrating’ the data?

    Hugo Messias (HM): We correct the raw data from the telescope for any system imperfection or inhomogeneous behavior. There are many things to correct for: for example, light is distorted and partially absorbed as it travels through Earth’s turbulent atmosphere, making the image blurrier and fainter. And even though the telescope system is state-of-the-art, it may introduce other imperfections in the light we receive from the Universe. We need to correct for all of these things to ensure that we have great data!

    Q. So has it been difficult to schedule observations of the black hole at the centre of Messier 87?

    4
    Analogue signals collected by the antenna are converted to digital signals and stored on hard drives together with the time signals provided by atomic clocks. The hard drives are then flown to a central location to be synchronised. Credit: ALMA (ESO/NAOJ/NRAO), J.Pinto & N.Lira

    RHI: Yes! The individual telescopes that make up the EHT are not fully dedicated to the EHT project; they are cutting-edge telescopes that astronomers use all year long to observe a variety of different objects. Once per year, all these telescopes agree to create a gap in their schedules to observe together as part of the EHT. But the observing time is very limited.

    During observing campaigns, we must decide every day if an observation is going to be triggered or if we are going to wait until the next day. If we decide to wait, all stations will continue their usual observations, but if we get the green light, everyone will observe the agreed black hole targets and a part of the valuable time set aside for the EHT is consumed. This decision is mainly based on the weather forecast, and it is a tough one. After all, it is not that common to have good weather in so many places in both hemispheres at the same time! Furthermore, there are some small details that make things even more interesting. For instance, communication with the South Pole Telescope in the middle of Antarctica is not steady, but restricted to the limited windows when telecommunication satellites pass above the telescope. Last minute decisions are not always an option.

    HM: During the observations, a plan is sketched and distributed among all observing facilities. This schedule has to be followed to very precise timings, so we know that all telescopes are pointing at the same source at the same time. When finished, the data obtained are sent to the data-combining correlators. The challenge is that some of the stations might have been shut due to poor weather conditions, or that the data take months to arrive. An extreme example of the latter is that data from the South Pole Telescope arrive at the correlators only 6–8 months after observation!

    Q. Thirteen partner organisations and more than 200 people are involved in this project. Why does it require such a huge international effort?

    HM: Imaging a black hole is incredibly difficult. Even though the black hole at the centre of Messier 87 is 6.5 billion times the mass of the Sun, it is very dense, and therefore relatively small. And it is 55 million light-years away, so from Earth it looks tiny! We have been trying to image the event horizon — the ‘point of no return’ around a black hole, beyond which light can’t escape. But to discern something so small, we need a huge telescope. And as we are measuring light that has wavelengths on the order of millimetres, we need a telescope the size of the Earth! This is physically impossible, so we used interferometry — which is the same technique that ALMA uses on a smaller scale — to connect telescopes around the globe to mimic an Earth-sized telescope. And that takes a huge international effort.

    Q. How are the telescopes synchronised?

    RHI: When using the technique of interferometry, it is essential to combine the signals from each telescope at the exact same time. One way to ensure the synchronisation is to connect every station with a fibre-optic link to a central supercomputer. But considering the remote locations of the EHT telescopes, this would clearly not have been an option! Instead, each telescope was equipped with an ultra-precise hydrogen maser atomic clock that precisely timed each observation. This made it possible to combine data later on.

    4
    The locations of the participating telescopes of the Event Horizon Telescope (EHT) and the Global mm-VLBI Array (GMVA). Credit: ESO/O. Furtak

    Q. Was it difficult to collaborate with other institutions all around the world?

    RHI: There are always challenges in coordination and communication among the many different people working in an observatory: astronomers, engineers, administrators and computing teams, to name just a few. Everyone must work together towards the same goal. ALMA is a huge observatory, with hundreds of workers from more than ten different countries, and some of the other observatories involved in the EHT project are almost as big. Now imagine eight of these observatories working together on a time critical, cutting-edge project, and you will get a grasp of how much fun a project like the EHT can be!

    Q. How does it feel to be part of an international collaboration that has made such an incredible discovery?

    HM: I feel honoured, proud, fulfilled, and hopeful. The latter is more related to the fact that we are showing that, despite the cultural differences, a team comprising individuals with distinct backgrounds had a common goal, and achieved it. That teaches the world another key lesson, besides the one being reported.

    Q. Is there anything else you would like to mention?

    HM: Aside from the people included in the author list of the papers, many other individuals enabled this discovery to happen. We are not only “standing on the shoulders of giants” who carved out the path towards the techniques and technology we currently use, but also on shoulders of hard-working people who build and maintain the antennas, correlators and software at these remote sites. This is what enabled the discovery to happen. To them, I say a big thank you, as well as to the curious society that provided the will and, of course, the funding. These contributions were key to making this feat a reality!

    See https://sciencesprings.wordpress.com/2019/04/10/from-european-southern-observatory-astronomers-capture-first-image-of-a-black-hole/ for lists with links.

    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

    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,


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

    ESO VLT 4 lasers on Yepun


    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.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 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 11:27 am on March 31, 2019 Permalink | Reply
    Tags: "Concealing the Cosmos", , , , , ESOblog, Light as a pollutant   

    From ESOblog: “Concealing the Cosmos” 

    ESO 50 Large

    From ESOblog

    1
    On the Ground

    29 March 2019

    Why light pollution makes it difficult for astronomers to observe on location.

    2
    Eleanor Spring

    When people find out that I am a professional astronomer, they tend to imagine that I spend my days (well, my nights) gazing up at the stars, adjusting telescopes and collecting images of the Universe. As my job as a PhD candidate is to study space, this is a reasonable response. So I am usually met with surprise when I tell people that in fact most astronomers spend very little of their time observing, and that I have never collected data for professional use, on location, myself. Why?

    The main justification for my lack of interaction with telescopes is the extraordinary amount of time, money and resources it takes to physically reach them. The inconvenient placement of modern telescopes is no accident. It is entirely deliberate, and serves the purpose of getting the telescopes as far away from human habitation as possible. ESO’s telescopes are located deep in the Chilean Atacama desert, with Paranal Observatory [below] (the home of the Very Large Telescope) located 130 km from the nearest city of Antofagasta. This is because where human beings are, light pollution follows.

    It’s strange to think of light as a pollutant. Our days are naturally filled with it, and our nights are made infinitely easier by its presence. Nonetheless, the relatively unchecked growth of humanity’s dwellings, infrastructure and technology has resulted in our night skies being flooded with excess light, both within and outside the visible range that human eyes are sensitive to. It is difficult for someone who was raised in a town or city to appreciate the impact of light pollution on our skies. It was not until a few years ago that I realised that, from the lonely isolation of the Chilean desert, the sky appears to be literally ripped apart by the spillage of the billions of stars that comprise our Milky Way.

    So what is the difference between light, and light pollution? An apt analogy is any other kind of waste product or pollutant. For example: a disposable coffee cup. The cup is only intended to hold coffee, not to be scattered on streets and contribute to landfills. But because we did not care to invent anything better, or reduce our intake of coffee, the disposable cups pile up and up until they start to affect our environment. The same is true for light pollution. Devices intended to light our homes, offices and streets spill surplus light, as waste, in unnecessary directions. This light scatters off the molecules and particles in our atmosphere, and infuses the night sky with a strange, dull glow. It is not intentional, but through poor design, excess use of artificial light and a general lack of care, humans have completely changed the night sky environment.

    3
    The setting Milky Way at La Silla Observatory. Despite La Silla’s remote location, bright city lights illuminate the horizon. Credit: ESO/P. Horálek

    This glowing means that the stars and planets in the night sky are no longer the sole source of photons (light particles). The excess light falls into telescopes and onto our eyes indiscriminately, greatly or entirely blocking out the visually stunning, and far more interesting light sources.

    But whilst this pollution is infuriating for astronomers, who have to resort to locating telescopes deep in the desert; high up mountains; or at the very poles of the Earth, is it anything more than an inconvenience for a handful of people? Sadly, yes. The impact of light pollution extends far beyond the loss of a readily available beautiful sky. The rhythm that our bodies naturally go through everyday is profoundly confused by artificial light at times we would naturally be sleeping. Light pollution has been correlated with insomnia, increased stress and issues regulating hormones.

    The effects extend far beyond the human race. The vast majority of evolutionary history has taken place without the influence of artificial light. Light pollution extending beyond the range that humans can see impacts insects, birds and animals, disorientating them and affecting entire ecosystems.

    If a dark night sky is of such importance, not just for the well-being and pleasure of humans, but of entire species of other living creatures, then what is being done to preserve them? Fortunately many organisations exist to combat the spread of light pollution. It is of course in ESO’s keenest interest to preserve our dark skies, and it works in collaboration with many of these initiatives.

    Certain areas of the world are already protected dark sky sanctuaries, including a small part of the Atacama Desert. People who want to make a difference on a more personal or local level have plenty of possibilities; to begin with, minimising light at night as much as possible. When unavoidable, it can be kept muted, and shaded from the sky with curtains or by capping the tops of lamps. In addition, as we see from the blue colour of the sky during the day, our atmosphere optimally scatters blue light. Whilst this is idyllic during our waking hours, at night, keep artificial lighting as reddish or yellowish as possible, to minimise scatter. If local government and individuals all start to implement these small changes, it would help everyone to admire the beauty of the night sky.

    In the meantime, from the perspective of astronomers, the long journey into the Atacama Desert is well worth it, giving us the opportunity to experience the extraordinary luxury of a sky relatively unaffected by mankind. Not only does it make truly stunning astrophotography possible, but it allows astronomers who observe using ESO telescope the chance to collect some of the most pristine data on Earth.
    Links

    Dark skies preservation at ESO

    Eleanor Spring is a former ESO science communication intern, who has continued her relationship with ESO as a freelancer, working as the Public Information Officer in charge of the ESO Pictures of the Week. She is currently living in Amsterdam and working on a PhD, developing techniques to characterise exoplanets, which provides the exciting opportunity to see another side of ESO — the use of data collected at their telescopes! She has also found other outlets for her love of communication: teaching yoga and (attempting) to learn Dutch and French.

    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,


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

    ESO VLT 4 lasers on Yepun


    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.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres


    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 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 4:10 pm on March 22, 2019 Permalink | Reply
    Tags: , , , , ESOblog, VVV-WIT-07, WIT-"What Is This" star   

    From ESOblog: “What Is This?” 

    ESO 50 Large

    From ESOblog

    22 March 2019

    1
    Astronomers discover mysterious star displaying never-seen-before behaviour.

    Many, if not most, stars vary in brightness, typically by just a little and very predictably. These changes occur on timescales from minutes to years, and can tell us about the internal structure of stars in a way that no other observations can. But recently, a team of astronomers used ESO facilities to discover an extreme variable star named VVV-WIT-07, with WIT being short for “What is this?”. Seen from Earth, this strange star suddenly and irregularly reduces in brightness by 30–40%. In one extraordinary case it even dimmed by about 80%. But “normal” stars just don’t do that. The research was led by Roberto Saito from the Universidade Federal de Santa Catarina. ESO astronomer Valentin Ivanov was involved in the research and tells us more.

    We made this discovery whilst searching for extreme variable stars in the innermost parts of the Milky Way using ESO’s VISTA survey telescope.

    3
    The Milky Way arcing over VISTA, the Visible and Infrared Survey Telescope for Astronomy, used to discover VVV-WIT-07. Credit: ESO/Y. Beletsky

    This was part of a survey of the Milky Way — named VISTA Variables in Via Lactea, or VVV for short — that we have been working on for many years. The survey is the first to image the most crowded and obscured regions of our home galaxy with high angular resolution at infrared wavelengths. The high angular resolution helps to separate the billions of stars that are superimposed close together on the sky and observing at infrared wavelengths makes it easier to see through the dust that — just like fog hides magnificent views on Earth — blocks our view of the most interesting parts of the Milky Way.

    2
    VVV-WIT-07 in the centre of a star field. Credit: Saito et al.

    A key word that could be used to describe our finding is extreme. In every aspect. Extreme objects are always the most interesting, because they push the limits of our knowledge beyond the well-known and well-understood comfort zone. The extreme places are where new discoveries await. And surveys like VVV are a great way to identify such objects because they scan a lot of the sky many times over.

    Whilst we have found a number of extreme objects through the VVV survey so far, possibly the most mysterious is the highly varying VVV-WIT-07, which doesn’t fit with any known class of variable star. Over eight years, we observed this star 85 times through the VVV survey. The first observations showed nothing strange — simply a mild scatter in the brightness measurements, consistent with the observational uncertainties. However, in August–September 2011, just before the end of the observing season, the star dimmed by a factor of almost two! By June 2012, when we began re-observing it, the star’s brightness was nearly back to normal. But by mid-July, it had dimmed by almost 80%! Then it was back to its usual self in about a week. The data taken since then contain hints of additional drops in brightness, but nothing so dramatic.

    Our first reaction was “this can not be” — this is just a healthy pessimism, common among scientists. But once we inspected the images and checked the observations, it was clear that we had come across something very strange.

    By June 2012, when we began re-observing it, the star’s brightness was nearly back to normal. But by mid-July, it had dimmed by almost 80%!

    Since making this discovery, we have been asking ourselves why this star varies so much in brightness, but that’s not a simple question to answer. One relatively likely possibility is that an object (or even multiple objects!) is orbiting VVV-WIT-07, passing between us and its host star, blocking some of the light. Given the drastic light loss, this object could a ringed exoplanet, but with extreme, giant rings, far larger than those of Saturn. Or it could be a family of comet-like objects that occasionally block up to 80% of the starlight.

    2
    Lightcurve of VVV-WIT-07 showing how it varied in brightness between 2010 and 2018. The insert shows an expanded view of the particularly dramatic dimming event that occurred in July 2012. Credit: Saito et al.

    Another possibility is that VVV-WIT-07 may be surrounded by a clumpy or warped disc, oriented nearly edge-on from our point of view, and the dips in brightness are caused by the clumps, or the warp, crossing the star and blocking its light.

    All these options involve extremely rare classes of objects. So far astronomers know of only one case each for a passing Saturn-like planet and comet family, and just a handful of cases of edge-on clumpy or warped discs. And the host stars in those cases don’t resemble VVV-WIT-07 at all.

    Indeed, VVV-WIT-07 is a strange object, fully justifying the “What Is This” in its name.

    3
    SPHERE image of dust rings around a nearby star. The disc is clumpy — something astronomers currently have no explanation for. It´s possible that this phenomenon is caused by the presence of planets. Credit: ESO/Perrot

    ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT MELIPAL UT3, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

    The possibility of finding new worlds is always fascinating, but we have identified a system that challenges the imagination even more than usual, because it is so unlike our own planetary system. The unusual dips in the observed brightness of VVV-WIT-07 remind us of the famous Boyajian’s Star, that dims as much as 22% — still a feeble amount compared to our star’s brightness reduction of 80%.

    Huge variations in brightness are common for stars in binary systems with two stars of near-equal mass, when one passes in front of the other. But through our observations we see clearly that VVV-WIT-07 is not a binary star. The only previously discovered non-binary star to dim by a comparable amount is Mamajek’s Object, which is the previously-mentioned star shadowed by a passing planet with a gigantic ring system.

    Further observations are needed before we will be able to draw a firm conclusion about what causes this phenomenon. We are continuing to monitor it, hoping to catch it in the act: during a dip. Then we will attempt to obtain new types of observations that should help us to find out what causes this strange behavior.

    See the full article here .


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    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 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 2:32 pm on March 1, 2019 Permalink | Reply
    Tags: "Radioactive planets", André de Castro Milone, , , , , , ESO 3.6m telescope & HARPS at Cerro LaSilla Chile 600 km north of Santiago de Chile at an altitude of 2400 metres, ESOblog, Jorge Luis Melendez Moreno, The presence of thorium is an indicator that any rocky planets around these stars may host plate tectonics which can trigger and support life   

    From ESOblog: “Radioactive planets” 

    ESO 50 Large

    From ESOblog

    1 March 2019
    Science Snapshots

    ESO 3.6m telescope & HARPS at Cerro LaSilla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    Searching for hints of life around the Sun’s galactic twins.

    Using the HARPS instrument on the ESO 3.6-metre telescope, a team of scientists recently carried out the largest ever search for thorium in stars that are almost identical to the Sun: solar twins. The presence of thorium is an indicator that any rocky planets around these stars may host plate tectonics, which can trigger and support life. We speak to two of the scientists involved in this search to find out whether these results have strengthened the claim for the existence of life elsewhere in the Milky Way.

    3
    André de Castro Milone

    4
    Jorge Luis Melendez Moreno

    Using the HARPS instrument on the ESO 3.6-metre telescope, a team of scientists recently carried out the largest ever search for thorium in stars that are almost identical to the Sun: solar twins. The presence of thorium is an indicator that any rocky planets around these stars may host plate tectonics, which can trigger and support life. We speak to two of the scientists involved in this search, André de Castro Milone and Jorge Luis Melendez Moreno, to find out whether these results have strengthened the claim for the existence of life elsewhere in the Milky Way.

    Q. Firstly, what is a solar twin and why are they so interesting to study?

    Andre de Castro Milone (AM): Solar twins are stars that are very similar to the Sun, for example in temperature, luminosity and chemical make-up. It is likely that the birth and evolution of these stars were also similar to the Sun’s birth and evolution, implying that planets may have formed around them in a similar way to how the planets formed in our own Solar System. This means that solar twins could be great places to start our search for life elsewhere in the Universe.

    Q. In this study you looked at the amount of thorium in 53 solar twins. Why thorium?

    AM: We looked at one specific type of radioactive thorium (Th-232). On Earth, the decay of such radioactive elements creates a heat flow in the convective mantle under the surface, which causes the tectonic plates on the surface to move. This makes Earth a geologically dynamic planet with earthquakes and volcanoes that contribute to the carbon cycle that regulates the temperature of the atmosphere.

    Jorge Luis Melendez Moreno (JM): As a stable atmosphere is closely related to the emergence and evolution of life, this means that the initial amounts of certain radioactive elements in a rocky planet contribute significantly to a planet’s ability to host life. Thorium is one of these elements that can be instrumental to the presence of life. It decays very slowly, meaning that it creates a gentle heat flow for a very long time, giving life a chance to thrive.

    Q. So why were you looking for thorium in the stars rather than in the planets themselves?

    JM: Because planets are so small and dim, it is extremely difficult to see thorium in them using current telescopes. It is much easier to find out how much thorium there is in their parent star. We used this information to figure out how much there was at the beginning of each star’s life. Planets form from a disc of gas and dust left over from the star’s formation, so knowing how much thorium there was in the star at the time of planet formation, we can estimate how much thorium went into a planet.

    Q. How exactly did you measure the amount of thorium in the stars?

    AM: We used the HARPS instrument on the ESO 3.6-metre telescope to capture very high-quality optical spectra from each star. Solar twins look white-ish from here on Earth, but HARPS can spread out the light into a spectrum to allow us to see that they actually emit light of a whole range of colours, or wavelengths. Each element in a star absorbs light at specific wavelengths, so spectra can be used to find out what elements are present. Using the spectra, we could make an estimation of how much thorium is currently in each star and knowing the rate of radioactive decay, we could estimate how much thorium was in each star when it formed.

    Q. And were you surprised by the amount of thorium you found in each star?

    JM: We didn’t really have an expectation about how much thorium might exist in solar twins, because a large study like this one had never been carried out before. So it would be more appropriate to say we were “excited” by what we found, rather than “surprised”.

    AM: It’s helpful to use the Sun as a comparison here, which is made up of mostly hydrogen atoms. In the Sun, there is just one thorium atom for every one trillion hydrogen atoms — that’s one with twelve zeros after it! We found that the amount of thorium varied in solar twins, but that it is 0.76–1.81 times as high as it is in the Sun, so about 1–2 thorium atoms for every trillion hydrogen atoms. Interestingly, we calculated that the thorium in the solar twins when they formed would have been about 1.09–1.37 times the initial thorium content of the Sun. This suggests that there could be plenty of thorium in any surrounding rocky planets, so they could be even more geologically active than Earth! This strengthens the argument that life could exist elsewhere in the Milky Way.

    JM: Possibly the most exciting thing is that we found thorium in stars with a variety of ages, meaning that life might be spread around not only in space, but also in time. There might be some really young life or some ancient life out there in the galaxy!

    4

    The spectrum of the Sun, with light spread out into separate wavelengths. Black lines show where light is absorbed by specific elements. One of the lines in the blue-violet region corresponds to the thorium that was studied in this investigation.
    Credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF

    Solar Fourier Transform Spectrometer, commonly called the FTS Tank, at the McMath-Pierce Solar Facility at NOAO Kitt Peak National Observatory Altitude 2,096 m (6,877 ft),


    Credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF

    National Solar Observatory at Kitt Peak in Arizona, elevation 6,886 ft (2,099 m)

    Q. Planets with atmospheres have already been discovered using other techniques. Why is this particular technique useful?

    JM: Indeed, lots of planets with atmospheres have been detected, but we still don’t know of any Earth-like planets around solar twins because other techniques are currently not able to detect them. Future telescopes such as the Extremely Large Telescope (ELT) will be capable of searching for signs of life on Earth-like planets around some stars, but unfortunately not Sun-like stars because it would take about a century to look at their atmospheres in sufficient detail.

    AM: Atmospheres are also not sufficient for life. Take Mars, for example. It has an atmosphere (which is thin due to its low surface gravity and lack of magnetic field) but no sign of current geological activity. Venus, on the other hand, shows signs of geological activity, but the atmosphere is extremely dense, with an out-of-control greenhouse effect. This was caused by an irreversible process — perhaps the evaporation of a huge amount of liquid water — and has led to Venus becoming unsuitable for life as we know it. Both Mars and Venus were of course formed around the same thorium-rich Sun as Earth was.

    So the existence of thorium on a planet is just one point in favour of the existence of life. Lots of other factors are involved that determine whether or not life is likely. But I believe that if we find enough solar twins, with enough geologically active planets around them, then we are likely to eventually find one that hosts life.

    Q. So would you like to use the ELT to carry out follow-up research?

    JM: We’d love to! The next step is to really look for planets around these solar twins. We have been using smaller telescopes such as the ESO 3.6-metre, and more recently have been observing solar twins with the Very Large Telescope. But later on, we would next like to use the ELT and even space telescopes to get a clearer picture of planets around solar twins and potentially find Earth 2.0!

    Until then, our main focus is on characterising the fundamental properties of solar twins, in particular their chemical composition and magnetic activity cycles, as those are vital steps towards understanding, and even discovering, planets around them.

    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 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 9:52 pm on February 15, 2019 Permalink | Reply
    Tags: "Space Cow Mystifies Astronomers", , , , , Could we be witnessing a dying star giving birth to an X-ray engine?, , ESOblog,   

    From ESOblog: “Space Cow Mystifies Astronomers” 

    ESO 50 Large

    From ESOblog

    1
    Science Snapshots – ALMA

    Could we be witnessing a dying star giving birth to an X-ray engine?

    15 February 2019

    One night in June 2018, telescopes spotted an extremely bright point of light in the sky that had seemingly appeared out of nowhere. Observations across the electromagnetic spectrum, made using telescopes from around the world, suggest that the light is likely to be the explosive death of a star giving birth to a neutron star or black hole. If so, this would be the first time ever that this has been observed. We find out more from Anna Ho, who led a team that used a variety of telescopes to figure out what exactly this mysterious object — classified as a transient and nicknamed The Cow — is.

    2
    Anna Ho

    Q. What is a transient, and why it is interesting to study them?

    A. The night sky appears calm but it is actually incredibly dynamic, with stars exploding in distant galaxies, visible through our telescopes as flashes of light. The word “transient” refers to a short-lived phenomenon in the night sky, which could be the explosion of a dying star, a tidal disruption event, or a flare from a star in the Milky Way. And there are probably many other types of transients out there that we have not even discovered!

    Q. So given that transients are sudden phenomena that you can’t predict, how can you possibly plan for studying them?

    A. It’s kind of a case of reacting to their appearance. In the past few years, we’ve entered this amazing new era of astronomy where telescopes can map out the entire sky every night. By comparing tonight’s map to last night’s map, we can see exactly what has changed over the previous 24 hours. The transients I study are very short-lived explosions — lasting between a few hours and a few months — so when an interesting one happens, we have to drop everything and react. Luckily I love my research enough to do this!

    It is only by using lots of different telescopes that we can really get a full picture of a transient.

    3
    ALMA and Very Large Array (VLA) images of the mysterious transient, The Cow.
    Credit: Sophia Dagnello, NRAO/AUI/NSF; R. Margutti, W.M. Keck Observatory; Ho, et al.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    Q. In June 2018, you observed an unusual transient that was named AT2018cow, or The Cow. Can you describe this phenomenon? What made it so remarkable?

    A. One night, astronomers saw a point of light in the sky that had not been there before: a new transient! The Cow was particularly special for two reasons: firstly, it was VERY bright, and secondly, it had achieved that brightness VERY quickly. This was exciting, because usually if a transient appears very quickly, it is not so bright, and a very bright transient takes a long time to become bright. So we realised immediately that this was something strange.

    Q. You chose to study this transient with two millimetre telescopes: the Submillimeter Array (SMA) and ALMA (Atacama Large Millimeter/Submillimeter Array). What do millimetre telescopes offer over other telescopes?

    CfA Submillimeter Array Mauna Kea, Hawaii, USA, Altitude 4,080 m (13,390 ft)

    A. In the early stages of a transient (in its first few weeks of existence), we can see the shockwave emitted by an explosion by capturing light at millimetre wavelengths — this is exactly what SMA and ALMA can see. In particular, thanks to ALMA we were able to learn that in the case of The Cow, the shockwave was travelling at one-tenth of the speed of light, that it is very energetic, and that it is travelling into a very dense environment.

    We also used the Australia Telescope Compact Array to look at light from the transient with longer wavelengths. It is only by using lots of different telescopes that we can really get a full picture of a transient.

    CSIRO Australia Compact Array, six radio telescopes at the Paul Wild Observatory, is an array of six 22-m antennas located about twenty five kilometres (16 mi) west of the town of Narrabri in Australia.

    By combining ALMA data with publicly available X-ray data, we were also able to conclude that there must be some ongoing energy production — a kind of continuously-running “engine” at the heart of the explosion. This could be an accreting black hole or a rapidly-spinning neutron star with a strong magnetic field (a magnetar). If The Cow does turn out to have either of these at its centre, it would be very exciting, since it would be the first time that astronomers have witnessed the birth of a central engine.

    Q. It seems that nobody’s quite sure what The Cow is. Why is there so much uncertainty still surrounding this object?

    A. It’s because the combination of The Cow’s properties is so unusual. It’s like that parable of the blind man and the elephant — where several blind men each feel a different part of an elephant and come to different conclusions about what it might look like. If you look at the visible light from The Cow, you might conclude that it is a tidal disruption event. On the other hand, if you look at the longer-wavelength light you see the properties of the shockwave and the density of the surrounding matter, and might conclude that it’s a stellar explosion. It’s incredibly difficult to reconcile all of the properties into one big picture.

    4
    Artist’s impression of a cosmic blast with a “central engine,” such as that suggested for The Cow. At the moment, the central engine is surrounded by dust and gas.
    Credit: Bill Saxton, NRAO/AUI/NSF

    Q. How will you find out what The Cow really is?

    A. Right now, the heart of the explosion is shrouded in gas and dust so it’s difficult to see it. Over the next months, this gas and dust will expand out into space, becoming thinner and more transparent, and allowing us to peer inside. When we are able to see into that central engine, we will be able to learn more about what it there, whether it’s a black hole, a neutron star, or something else entirely.

    Q. What do you think The Cow is, and why?

    A. Personally, I think it’s most likely to be a stellar explosion. Our ALMA observations enabled us to measure the surrounding environment to be incredibly dense — 300 000 particles per cubic centimetre! This kind of density is typical of a stellar explosion. Some people suggest it’s a tidal disruption event, but I think this would be difficult to explain. That said, I’m far from an expert on tidal disruption, so I look forward to hearing more from theorists on how to reconcile that model with our observations.

    Q. So what are the implications of this discovery? What does The Cow teach us about transients?

    A. From my perspective, The Cow is incredibly exciting for two reasons. One is astrophysical — what it can teach us about the death of stars. We think we’ve witnessed the birth of a central engine, an accreting black hole or a spinning neutron star, for the first time.

    The second reason is technological — we learned that this is a member of a whole class of explosions that in their youth emitted bright light at millimetre wavelengths. In the past, millimetre observatories like ALMA were rarely used to study cosmic explosions, but this study has opened the curtain on a new class of transients that are prime targets for millimetre observatories. Over the next few years, we hope to discover many more members of this class, and now we know that we should use millimetre telescopes to study them!

    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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 4:33 pm on February 14, 2019 Permalink | Reply
    Tags: , , , , , ESOblog, High-z Supernova Search Team, Supernova Cosmology Project at Lawrence Berkeley National Laboratory,   

    From ESOblog: “A Nobel Achievement (part II)” Bruno Leibundgut 

    ESO 50 Large

    From ESOblog

    1

    3
    Bruno Leibundgut

    8 February 2019
    People@ESO

    In 2011, the High-z Supernova Search Team won the Nobel Prize in Physics for the discovery that the expansion of the Universe is accelerating. Bruno Leibundgut, ESO’s Very Large Telescope Programme Scientist, was one of two ESO scientists who contributed to this extraordinary discovery, with the other being Jason Spyromilio. Bruno tells us the story of this game-changing piece of astronomical research in the second post in a two-part series about this prize-winning discovery.

    Also see: A Nobel Achievement (part I) https://sciencesprings.wordpress.com/2019/02/01/from-esoblog-a-nobel-achievement-part-i-bruno-leibundgut/

    At the beginning of the 1990s, the biggest question in astronomy was probably: what is the future of the Universe? Is it going to collapse? Or will it expand forever? Nobody knew.

    At the time many astronomers were looking at type Ia supernovae, which are the extremely bright explosions that occur when two stars in a binary system merge. This type of supernova always produces a similar amount of light, so we know how far away they are by how bright they look from Earth. And because they are so bright, we can often see supernovae even when they are really distant. This all means that we can use type Ia supernovae to find out about the past and future of the Universe; by comparing the apparent distance predicted by their brightness to their actual distance, it is possible to determine whether the expansion of the Universe has decelerated since the explosion occurred.

    2
    Artist´s impression of a binary system before and after merging to create a supernova. Credit: ESO

    I was working as part of a team that was trying to do just that. In 1995 and 1996, team member Adam Riess collected our observations on the brightness of ten distant supernovae, and the and team leader Brian Schmidt compared their distances and their brightnesses.

    They came up with the result that the expansion of the Universe was not decelerating. This was very surprising as we had expected that all the matter in the Universe is pulled together by gravity, leading to a decelerating expansion. But then in December 1997, Adam said to us: “Those distant supernovae are too far away. It’s like something has pushed them away from us. Could it be that the expansion of the Universe is actually accelerating?”

    This sparked a heated discussion — via email as the team was distributed all over the world! Brian was in Australia, Adam was on the west coast of the US, we had people on the east coast, we had people in Hawaii. And I was in Germany working with the data from the ESO telescopes. We would send an email in the evening and get up in the morning to find out about a number of other issues. But in the end, Adam and Brian could prove that there was no obvious mistake in the analysis. [Saul Perlmutter heads the Supernova Cosmology Project at Lawrence Berkeley National Laboratory at the same time with the same goal. He shared the Nobel prize with Adam Riess and Brian Schmidt.]


    In this much sped-up artist´s impression showing a collection of distant galaxies, the occasional supernova can be seen. Each of these exploding stars briefly rivals the brightness of its host galaxy. Credit: ESO/L. Calçada

    So, we decided we would have to submit a paper presenting our results, and we were sure that someone else would tell us what was wrong. But this didn’t happen. There were some people who didn’t believe us, but they were in the minority, and they couldn’t prove we were wrong.

    I’m not sure we were fully aware at the time what a big deal this discovery was. The fact that the expansion of the Universe is accelerating means that there must be some invisible “thing” in the Universe driving the expansion, causing the objects in it to flow apart faster than we would expect even for a universe without matter. The calculations tell us that this “thing” must be about three quarters of the energy content of the Universe. In a way, this was like discovering three quarters of the Universe that people had no idea existed.

    We were helped by another discovery made around the same time, related to the Cosmic Microwave Background (CMB).

    3
    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    People were using the CMB to study the geometry of the Universe. The tiny temperature fluctuations in the CMB indicated that the geometry of spacetime is flat, which requires a specific amount of matter and energy. Einstein’s famous equation E=mc2 tells us that mass (matter) and energy are equivalent. But determinations of the amount of matter and energy known to exist in the Universe made up just 25% of the amount required by a flat Universe. In other words, 75% of the matter and energy was missing.

    This value matched perfectly with our discovery of the extra energy component that makes up three quarters of the matter/energy content of the Universe. It was the combination of the two discoveries at almost the same time that convinced most people.

    This new component is now called dark energy. But more than twenty years later, we still have no idea what dark energy actually is! There is no physical explanation for it, but astronomers all over the world are working to find one.

    This discovery certainly affected my career. All of a sudden, I became one of the best-known observational cosmologists in Europe, which came with its pros and cons.

    As one of only two Europeans on the High-z Supernova Search Team, I got invited to many, many conferences here in Europe to present the result, and was asked to write major review papers on it. This took a lot of time out of my research.

    And then in 2011, Adam Riess and Brian Schmidt won the Nobel Prize in Physics for this research — they each won a quarter, and Saul Perlmutter of the Supernova Cosmology Project won the other half. We all went along for the Nobel Prize celebrations, which was an amazing experience.

    4
    The High-z Supernova Search Team just after the Nobel Prize award ceremony. Bruno stands on the right and Jason Spyromilio on the left of the back row.
    Credit: Nicolas Suntzeff

    But in the long run, I decided that I didn’t want to be part of large collaborations any more. The High-z Supernova Search Team wasn’t that big — around 25 people — but there were still so many teleconferences and meetings. I just felt tired of all that. I wanted to do things that I could be recognised for directly, rather than being a member of a team. I wanted to create something that people could recognise as coming from me.

    I’m still doing cosmology, though not the same type any more. That kind of research now requires large teams of hundreds of people. I’ve started to pick smaller problems again — things that I can do with students, to solve some of the smaller questions that we have about supernovae. It’s interesting to come from a big stage, from a place where the whole world pays attention to you, to go back to smaller problems that are not necessarily seen by everybody, and maybe not even seen as interesting by a lot of people. But that’s OK.

    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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 1:34 pm on February 1, 2019 Permalink | Reply
    Tags: , , , , , Dark Energy and the expansion of the universe, , ESOblog, The High-Z Supernova Search Team, The Supernova Cosmology Project   

    From ESOblog: “A Nobel Achievement (part I)” Bruno Leibundgut 

    ESO 50 Large

    From ESOblog

    1
    People@ESO

    How it feels to be part of a team that makes a Nobel Prize-winning discovery.

    Just over seven years ago, the Nobel Prize in Physics was awarded “for the discovery of the accelerating expansion of the Universe”. ESO’s Very Large Telescope Programme Scientist, Bruno Leibundgut, was part of the team that won. In the first post of a two-part series about Bruno’s career, we ask him about his experience at the Nobel Prize celebrations. The second post will be released next Friday and will focus on the science behind the prize.

    Q. First of all, could you tell us about the amazing discovery that gained your team a Nobel Prize in Physics?

    Twenty years ago, it was known that the Universe is expanding, that other galaxies are moving away from us and from each other. But the big question at the time was: will the expansion continue forever or will it stop at some point in the future, causing the Universe to collapse? Our team — the High-z Supernova Search Team — was trying to answer this question when we were surprised to find that distant objects were further away than expected in a freely expanding Universe.
    _________________________________________________
    The High-Z Supernova Search Team was an international cosmology collaboration which used Type Ia supernovae to chart the expansion of the universe. The team was formed in 1994 by Brian P. Schmidt, then a post-doctoral research associate at Harvard University, and Nicholas B. Suntzeff, a staff astronomer at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. The original team first proposed for the research on September 29, 1994 in a proposal called A Pilot Project to Search for Distant Type Ia Supernova to the CTIO Inter-American Observatory. The original team as co-listed on the first observing proposal was: Nicholas Suntzeff (PI); Brian Schmidt (Co-I); (other Co-Is) R. Chris Smith, Robert Schommer, Mark M. Phillips, Mario Hamuy, Roberto Aviles, Jose Maza, Adam Riess, Robert Kirshner, Jason Spiromilio, and Bruno Leibundgut. The original project was awarded four nights of telescope time on the CTIO Victor M. Blanco Telescope on the nights of February 25, 1995, and March 6, 24, and 29, 1995.


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    The pilot project led to the discovery of supernova SN1995Y. In 1995, the HZT elected Brian P. Schmidt of the Mount Stromlo Observatory which is part of the Australian National University to manage the team.

    The team expanded to roughly 20 astronomers located in the United States, Europe, Australia, and Chile. They used the Victor M. Blanco telescope to discover Type Ia supernovae out to redshifts of z = 0.9. The discoveries were verified with spectra taken mostly from the telescopes of the Keck Observatory, and the European Southern Observatory.

    In a 1998 study led by Adam Riess, the High-Z Team became the first to publish evidence that the expansion of the Universe is accelerating (Riess et al. 1998, AJ, 116, 1009, submitted March 13, 1998, accepted May 1998). The team later spawned Project ESSENCE led by Christopher Stubbs of Harvard University and the Higher-Z Team led by Adam Riess of Johns Hopkins University and Space Telescope Science Institute.

    In 2011, Riess and Schmidt, along with Saul Perlmutter of the Supernova Cosmology Project, were awarded the Nobel Prize in Physics for this work.

    The Supernova Cosmology Project is one of two research teams that determined the likelihood of an accelerating universe and therefore a positive cosmological constant, using data from the redshift of Type Ia supernovae.[1] The project is headed by Saul Perlmutter at Lawrence Berkeley National Laboratory, with members from Australia, Chile, France, Portugal, Spain, Sweden, the United Kingdom, and the United States.

    The work for this project was carried out at the Wm Keck Observatory, Maunakea, Hawai’i, USA


    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    This discovery was named “Breakthrough of the Year for 1998” by Science Magazine and, along with the High-z Supernova Search Team, the project team won the 2007 Gruber Prize in Cosmology and the 2015 Breakthrough Prize in Fundamental Physics. In 2011, Perlmutter was awarded the Nobel Prize in Physics for this work, alongside Adam Riess and Brian P. Schmidt from the High-z team.
    _________________________________________________
    It appeared that they were somehow being pushed away…we had found that the Universe was not only expanding — it was accelerating! This means that not only is there normal matter in the Universe, but also another component that we cannot see, that pushes space apart. This unknown entity is now called dark energy.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Q. Half of the Nobel Prize went jointly to your team members Adam Riess and Brian Schmidt. Why were they the ones to receive the prize, and what was your role in the team?

    A. Brian Schmidt was the team leader; he formed the team in 1994. Adam Riess collected most of the data in 1995 and 1996, which included information about the brightness of ten distant supernovae. Brian asked me to join the team to bring some ESO observing time…it’s hard to define what exactly every team member’s contribution was, but I worked a lot with the data that we gathered using ESO telescopes. I was also part of the discussions about the implications of the data.

    2
    Bruno Leibundgut at the Nobel celebration in Stockholm in 2011. Bruno was part of the winning team of the Nobel Prize in Physics, awarded for the discovery that the Universe is expanding at an accelerating rate. Credit: Jutta Tiemann

    Q. Can you tell us about your week in Stockholm, where the Nobel Prize was awarded? What did you do while you were there? What was the atmosphere like?

    A. It was an extremely full week! Aside from the award ceremony itself in Stockholm’s National Theatre, there was also a Nobel concert, attended by the Queen of Sweden, to which we were invited by the Nobel Prize winners. There were so many receptions and celebrations throughout the week, and it was even busier for the winners!

    The winners, Adam Riess and Brian Schmidt, were very kind. They used their prize money to invite all of the team members, plus their partners, to the ceremony for the whole week. We even got to stay in the same fancy hotel as they did: the Grand Hotel in Stockholm.

    Lots of our colleagues were there, including the other winning team, the Supernova Cosmology Project. The two teams had been in strong competition, because we were working towards the same result at the same time, sometimes even using the same instruments. That week, though, the competition fell away, because we were all winners and we had all contributed to this discovery. It was wonderful because we had the chance to discuss a lot, to talk about past experiences, things that occurred during the experiments. There was a lot of reminiscing and a lot of fun.

    Q. What was the most special moment for you during the celebrations?

    A. There were plenty of special moments, as the event is an incredible celebration of scientific research. One moment that stands out took place at the post-ceremony party. I bumped into Brian Schmidt, congratulated him and said: “Look, you’re a different person now, a certified genius!” He turned to me and said, “But Bruno, nothing will change between us.” And it’s true — now we meet less than once a year, but our relationship remains close.

    3
    ESO 1-metre Schmidt Telescope image of the Tarantula Nebula in the Large Magellanic Cloud. Supernova 1987A is clearly visible as the very bright star slightly to the right of the centre.
    Credit: ESO

    3
    The ESO 1-metre Schmidt telescope at La Silla began its service life in 1971 using photographic plates to take wide-field images of the southern sky.

    Q. What current questions in astronomy do you wish you knew the answers to?

    A. Oh, there are so, so many! It would be wonderful to understand more about dark energy. What is it? Where does it come from? What’s the physical basis for it? We’re pretty much searching in the dark — literally! We haven’t really made progress in this field over the last ten years but we hope that with the Extremely Large Telescope [below], we will be able to shed light on this mystery.

    Q. What do you love most about astronomy?

    A. I love the detective work: the fact that you can work away at a problem for years, debate it with friends, look at it from different angles, and then suddenly you have a breakthrough and see something you’ve never seen before. I also love the ingenuity: the way that we have to devise our experiments without being able to touch our subjects. We can’t modify the sky or the stars: we just have to take them as they are, and employ our physical intuition to understand what we see.

    One of the things I have focused on over the course of my career is Supernova 1987A, which I had the chance to see in the sky with my own eyes. Every time we look at it with the Very Large Telescope or the Hubble Space Telescope, we find something else unexpected — it’s amazing to be continually mesmerised by what this single object is doing. It’s beautiful because it’s an object that changes on the same timescale as a human lifetime, and it exploded at the beginning of my career. I look forward to seeing what else we can learn about it.

    Sgr A* from ESO VLT

    Biography Bruno Leibundgut

    After a Physics degree and a PhD in Astronomy, Swiss astronomer Bruno Leibundgut found himself in the United States for two postdoctoral positions. Returning to Europe in 1993, Bruno started working at ESO in a group that defined how the VLT would be operated. After a couple of years he became Deputy VLT Programme Scientist, then in 1999 moved on to building up the data quality control group, connected to the archive. Bruno was Head of Office for Science for eight years, then Director for Science for six years, before closing the circle by becoming VLT Programme Scientist four years ago.

    People@ESO shares stories of the people at ESO who are driving forward the world’s most advanced ground-based telescopes. Find more blog posts from guest bloggers and interviews with astronomers here on the ESOblog.

    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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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 2:15 pm on January 26, 2019 Permalink | Reply
    Tags: , , , Black tape, , ESOblog, SPHERE Adaptive Optics on the VLT, Spiders   

    From ESOblog: “Warming up spiders on the Very Large Telescope” 

    ESO 50 Large

    From ESOblog

    25 January 2019

    1
    HighTech ESO

    Never underestimate the value of black tape.

    After years of planning, in 2014 ESO’s Very Large Telescope welcomed the planet-hunting SPHERE instrument.

    ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT MELIPAL UT3, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

    Ever since, SPHERE has enabled scientists to carry out ground-breaking astronomical research, including investigating how planetary systems are formed. But SPHERE experienced some teething problems from the very beginning. When experiencing little or no wind, the images it produced were of a much poorer quality than when the wind blew with more force. At first, this paradox baffled engineers, but they quickly donned their detective hats to figure out what exactly was going on. ESO’s Markus Kasper tells us how he worked as part of a team of experts to understand and solve this problem.

    Q. Other than being a telescope-detective, what is your role at ESO?

    A. My official title is “Adaptive Optics Scientist”, although “telescope-detective” sounds good as well! In reality, I sit at the meeting point between adaptive optics, instrumentation and astronomy. Adaptive optics is a relatively new astronomical technique where deformable mirrors on telescopes correct in real-time for the distortion of light caused by the turbulence in Earth’s atmosphere. My role mostly involves work on instruments, especially for the Very Large Telescope (VLT), but I also dabble in astronomy, in particular in the fields of exoplanets and star formation.

    Q. What was the problem you noticed when SPHERE was first switched on, and what were the clues that led you to understand this problem?

    A. We noticed that SPHERE’s adaptive optics system didn’t perform well on a significant fraction of nights, resulting in poor quality images. Clue one was the realisation that the nights it performed badly were nights that had especially low wind conditions. This was particularly annoying because such gentle conditions usually lead to the sharpest images, as the light is not blurred and distorted much on its way through the atmosphere. So on the nights where we should have been getting fantastic images, we were actually getting very poor ones.

    Many telescopes, including most of ESO’s telescopes, host a large secondary mirror supported by mechanical struts that are rather imaginatively called “spiders”. When the spiders are colder than the surrounding air, the air cools down when it comes into contact with them. The density of air increases as it cools, which means that its refractive index increases. This results in light becoming distorted as it moves through the cold air. Clue two was that the VLT’s secondary mirror was indeed supported by such a spider.

    Putting the two clues together, we realised that the telescope’s spider was causing SPHERE’s adaptive optics to perform poorly. Most wavefront sensors used in adaptive optics systems can’t measure and correct for the distortion caused by the cooler spiders interacting with the warmer air, so the resulting image is degraded. This was the first time ever that anyone had realised this image-blurring effect of the cool spiders, so we had free reign to call it whatever we wanted. At first, we nicknamed it the “Mickey Mouse Effect” because it often led to images with two side lobes that looked like Mickey Mouse’s ears! Upon further consideration, we decided that naming it the “Low Wind Effect (LWE)” sounded a little more professional…

    It is only now, in retrospect, that we realise this effect is something that has severely hampered the performance of adaptive optics systems not only at Paranal Observatory, but around the world.

    2
    A demonstration of how the Low Wind Effect (LWE) affects astronomical images. Credit: Milli et al.

    Q. Why is it called the “Low Wind Effect”?

    A. It seems a bit counter-intuitive but this effect occurs when the wind blows gently, because the lower the wind speed, the longer one bit of air is in contact with the spider. This means that more heat is transferred from the air to the spider, and so the air cools down more. When the wind is strong, air is quickly blown away from the spider, so doesn’t have much time to transfer heat.

    It’s the same when you touch a very cold object. If you have your hand on it for just a fraction of a second, you barely notice the cold because your skin has little time to transfer heat. But holding your hand there for several seconds becomes painfully cold because your skin loses so much heat to the object.

    3
    APEX helps astronomers observe the cold and distant Universe. APEX’s secondary mirror is visible at the top of this image, supported by a spider.
    Credit: F. Montenegro-Montes/ESO/APEX (MPIfR/ESO/OSO)

    Q. So you’d successfully figured out what the problem was. How did you then go about finding a solution?

    A. The main reason why the spider was colder than the air was because it was constantly emitting energy into the night sky. The same effect cools down things that are outside at night below the dew point, leading to morning dew.

    We figured that the Low Wind Effect wouldn’t be possible if the telescope spider was the same temperature as the air. So the solution was simply a matter of us carefully analysing how air is cooled down by a colder structure that it comes into contact with and then working out how to keep the temperature of the spider as close to the temperature of the air as possible.

    Sadly the solution wasn’t as simple as just wrapping the spider in a blanket. Instead, we considered several other strategies to reduce the problem, including actively heating the spider, correcting the resultant blurring, and attacking the root cause of the problem by preventing the spider from being able to emit energy.

    In the end, we went for this third option, which I suppose is actually somewhat similar to wrapping the spider in a blanket! The old spider surface very efficiently emitted radiation, so we decided to cover it with a new surface that doesn’t radiate efficiently. The solution involved finding a tape coated with a special material with the right properties and wrapping this tape around the spider arms.

    It sounds like a cliche but I would like to highlight that this solution really was a team effort! Three groups of researchers — one from the SPHERE consortium, one from Paranal and one from ESO HQ — worked together to understand the effect, and develop mitigation strategies. The fact that this fix to the world’s most advanced optical instrument involved something as simple as tape is of course a bit funny, but — again to sound a bit more professional — I should mention that this tape is really unique and is also used on spacecraft.

    4
    One of the four spider arms with the top beam covered with the new tape and the bottom beam still uncovered. Credit: Milli et al.

    Q. And has the solution work as well as you’d hoped it would?

    A. The solution was very effective. Ever since we implemented it, we’ve rarely observed the Low Wind Effect, and when it has occurred during really exceptionally low wind speed conditions, the image degradation was not bad at all compared to how it was previously. This is very good news not only for SPHERE, but for all instruments on Paranal that make use of adaptive optics.

    The VLT is made up of four Unit Telescopes (UTs). The tape was first applied to the spider supporting the secondary mirror of UT3, home to SPHERE, and proved so effective that has now been applied to UT4, which hosts other adaptive optics instruments. Designers of the future Extremely Large Telescope also plan to use this method on parts of its structure. Looks like I need to go and invest in some more tape!

    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-

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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 VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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 2:38 pm on January 19, 2019 Permalink | Reply
    Tags: , , , , Disentangling starlight, ESOblog   

    From ESOblog: “Disentangling starlight” 

    ESO 50 Large

    From ESOblog

    1

    Although they look like fuzzy patches of light, distant galaxies are actually made up of billions of stars and other astronomical intricacies. Telescopes are rarely powerful enough to study the individual stars in galaxies except for those closest to the Milky Way, but a team of scientists has now used the MUSE instrument on ESO’s Very Large Telescope to resolve the stars in the spiral galaxy NGC 300.

    ESO MUSE on the VLT on Yepun (UT4)

    By telling the story of how astronomy has reached this point, team member Martin M. Roth from the Leibniz Institute for Astrophysics Potsdam helps us understand why this result is so exciting.

    Four hundred years ago, Galileo Galilei became the first person to point a telescope at the sky and prove that the hazy band of the Milky Way is actually composed of billions of individual stars. Astronomy has come a long way since then, and nowadays astronomers do not merely look at the stars, but also analyse their chemical composition, measure their rotation and velocity in space, and determine many other physical parameters to find out more about the Universe — all using a technique called spectroscopy, which is the study of the interaction of matter and light.

    Stellar spectroscopy really started taking speed with the emergence of a technique called integral field spectroscopy, around the same time that I joined Leibniz Institute for Astrophysics Potsdam (AIP) as a young astronomer in the early 1990s. This technique allows astronomers to obtain a 3D view of a galaxy in just one shot. It uses an Integral Field Unit (IFU) to divide the field of view into many segments — or pixels — to obtain a more comprehensive overview of the whole. The signal from each pixel is fed into a spectrograph which generates a light spectrum for each one. The pixels in this case are rather lovingly named “spaxels”.

    Even all those years ago it occurred to me that such a device could be used to disentangle the stars in crowded fields, such as in star clusters and distant galaxies, where the light from stars blends together to become a blurry blob. So by 1996, our team at Potsdam had begun to develop our own integral field spectrograph. We called it PMAS — the Potsdam Multi-Aperture Spectrophotometer.

    1
    How integral field spectroscopy works. Credit: ESO

    Several research groups were developing integral field spectrographs at the same time, but the main drawback to all of them was the number of spaxels. PMAS, for example, hosted a mere 256 of them — compare this to your phone camera, which probably has something like 10–15 million pixels. This all changed dramatically with the arrival of MUSE, the Multi Unit Spectroscopic Explorer, on ESO’s Very Large Telescope (VLT). MUSE hosts an incredible 90 000 spaxels and boasts superb sensitivity.

    The primary raison d’etre of MUSE is to study the origin and development of the Universe as a whole, but when ESO invited proposals for MUSE pilot studies almost five years ago, I applied to use the new instrument to try to resolve stars in the nearby spiral galaxy NGC 300. This had already been done for very nearby galaxies in what is called the Local Group but never for galaxies further afield.

    Thankfully, my proposal to observe NGC 300 was chosen as one of the MUSE pilot studies, and we were given observing time! At a distance of six million light-years from the Milky Way, NGC 300 is just outside the Local Group and is what I would describe as a very “typical” spiral galaxy; finding out more about it should help us find out more about how spiral galaxies work in general.

    2
    The intricate network of pipes surrounding the 24 spectrographs of the MUSE instrument on the VLT. The instruments complexity is equaled by its power and productivity. Credit: A. Tudorica/ESO

    But it wasn’t enough just to observe the galaxy using MUSE, it was also necessary to develop some software that could help us visually separate the stars in the MUSE data. A talented doctoral student within our research group created a novel tool to do this. To test the tool, we used our old PMAS spectrograph on a telescope at the Calar Alto Observatory in Spain to measure the speed of some stars in Milky Way star clusters. The tool worked perfectly!

    Calar Alto Observatory located in Almería province in Spain on Calar Alto, a 2,168-meter-high (7,113 ft) mountain in Sierra de Los Filabres

    We then tried out the tool with MUSE images of a cluster of Milky Way stars before the real test — would it work on NGC 300, a galaxy 800 times further away than this star cluster?

    The results turned out to be better than we could have ever imagined! We could see individual stars with incredible clarity and gaseous regions, such as supernova remnants, planetary nebulae, and ionised hydrogen regions were revealed. Amazingly, we could even see dim background galaxies through NGC 300! MUSE is special because it can look at light with a wide range of wavelengths, making many different objects and colours visible.

    4
    This picture of the spectacular southern spiral galaxy NGC 300 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

    It was assembled from many individual images through a large set of different filters over many observing nights, spanning several years. The main purpose of this extensive observational campaign was to get an unusually thorough census of the stars in the galaxy, counting both the number and varieties of stars and marking regions, or even individual stars, that warrant deeper and more focussed investigation. But such a rich data collection will also have many other uses for years to come.

    The images were mostly taken through filters that transmit red, green or blue light. These were supplemented by images through special filters that allow through only the light from ionised hydrogen or oxygen gas and highlight the glowing clouds in the galaxy’s spiral arms. The total exposure time amounted to around 50 hours.

    Credit: ESO

    5
    The new MUSE images of NGC 300 laid over the WFI image, with individual stars clearly visible. Credit: ESO

    After so many years of preparation, involving the hard work of so many individuals, it’s fair to say that we were overwhelmed when we received the NGC 300 data. But we have merely scratched the surface of a gold mine. We have so much more data to analyse that we have gathered a team of enthusiastic astronomers to go through it, all keen to discover what lies beyond what we once thought was impossible. And through it all, I keep reminding myself that this was a pilot study.

    Not only do we hope to use MUSE to look at even more galaxies, ESO is currently building an instrument called 4MOST that will be dedicated to disentangling starlight and imaging up to 2400 individual stars per single exposure in the Milky Way. The goal is to study millions of stars in the attempt to unravel our galaxy’s formation history and evolution, as part of a vibrant field of research called “galactic archaeology”.

    But MUSE is already enabling “extragalactic archaeology” for the first time ever. With its ability to collect huge amounts of light and create incredibly sharp images, ESO’s Extremely Large Telescope will be able to take extragalactic archaeology even further, investigating individual stars in other galaxies to help us find out more about the Universe.

    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 EEuropean Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

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

    ESO VLT 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


    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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