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  • richardmitnick 9:45 pm on June 18, 2021 Permalink | Reply
    Tags: "Capricious Cosmos", , , , , , , ESOblog (EU), , Merging neutron stars   

    From ESOblog (EU): Women in STEM-Cyrielle Opitom “Capricious Cosmos” 

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    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) (CL)

    18 June 2021
    Science@ESO

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    Juan Carlos Muñoz Mateos.
    Juan Carlos Muñoz Mateos is Media Officer at ESO in Garching and editor of the ESO blog. He completed his PhD in astrophysics at Complutense University of Madrid[Universidad Complutense Madrid](ES) . Previously he worked for several years at ESO in Chile, combining his research on galaxy evolution with duties at Paranal Observatory.

    Astronomical observations are usually planned months in advance, which is not a problem as most celestial objects remain unchanged for millions if not billions of years. But certain astronomical phenomena can occur unexpectedly on timescales of just days –– sometimes even minutes. To learn how we can deal with these sudden events we have talked to three astronomers who study some of the most unpredictable phenomena in the Universe.

    “Comets are like cats: they have tails and they do precisely what they want.” This quote by David H. Levy, an amateur astronomer who co-discovered a comet that impacted on Jupiter in 1994, perfectly describes the capricious personality of comets –– large blocks of ice and rock that traverse the solar system.

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    A NASA Hubble Space Telescope (HST) image of comet Shoemaker-Levy 9, taken on May 17, 1994, with the Wide Field Planetary Camera 2 (WFPC2) in wide field mode.

    But these aren’t the only unpredictable objects out there. Violent supernova explosions, black holes gobbling material from closeby stars, or neutron stars smashing against each other are just a few examples of astronomical phenomena known for not caring about the daily routine of the astronomers who study them. How can we observe these events without even knowing when or where they will happen? Let’s find out.

    Celestial wanderers

    Cyrielle Opitom, a former ESO Fellow and now a Royal Astronomical Society (UK) Norman Lockyer Research Fellow at the University of Edinburgh (SCT), is very familiar with the changeable nature of comets –– fossils that allow us to study how our own solar system formed and evolved. “Comets are very unpredictable,” she says. “Some suddenly split into different fragments, crash into a planet, or become ten times brighter from one day to the next. And we are still trying to understand why those things are happening. That also makes comets very fun to study. You never know what to expect and it never gets boring.”

    When a comet gets close to the Sun, its ices become gaseous. This ejects dust particles as well, creating a huge envelope of dust and gas around the nucleus of the comet, called ‘coma’. Cyrielle uses spectroscopy, a technique that splits light into its constituent colours or wavelengths, “to detect molecules in the coma, and to know what cometary ices are made of.”

    But it’s hard to know in advance when a comet may undergo a sudden burst of activity. To address this, ESO and other observatories offer a type of observing programme called “Target of Opportunity”. “This allows us to decide in advance that we want to observe an outburst of activity, have the observations ready to be executed, and when an event is detected we can ask for the observations to be done within just a few days,” says Cyrielle.

    A Target of Opportunity still requires astronomers to submit an observing proposal months in advance describing their scientific idea, even if they don’t know when they will trigger the observations. “But there are events that we can’t predict, or new interesting comets that are discovered after the deadline for observing time proposals has passed.” For situations like these, observatories offer the opportunity to obtain observing slots using “Director’s Discretionary Time (DDT)”, which allows astronomers to submit an observing proposal on-the-fly for urgent scientific reasons. For instance, these DDT slots came in handy to observe 2I/Borisov, the first interstellar comet, immediately after its discovery, allowing astronomers to study this alien visitor while it was still close to the Earth.

    Comets can still surprise you even when you are already pointing a telescope at them, as Cyrielle knows all too well. In December 2018 she was observing comet 46P/Wirtanen with the ESPRESSO spectrograph at the UT3 telescope [1], part of ESO’s Very Large Telescope.

    “The comet was bright and very close to the Earth,” she says, “so it was quite big in the sky. However, when we tried to point the instrument at the comet, we could not find it.”

    As it turns out, the comet was too far from its predicted position. Luckily, she was observing it simultaneously with the UVES spectrograph on the UT2 telescope. “We managed to find it with UVES, which has a larger field of view.

    We computed the offset from the predicted position and finally found the comet with ESPRESSO as well. But our problems were not over: the comet was not moving the way we expected, so we had to constantly adjust the position of the telescope during the observations. Thanks to the great skills of our support astronomer we got amazing data in the end.”

    When black holes take a midnight snack

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    Combining observations done with ESO’s Very Large Telescope and NASA’s Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole.

    The black hole blows a huge bubble of hot gas, 1000 light-years across or twice as large and tens of times more powerful than the other such microquasars. The stellar black hole belongs to a binary system as pictured in this artist’s impression. Credit:L. Calçada/M.Kornmesser/ESO.

    Black holes may not be as evasive as comets, but they are still tricky to observe. Teo Muñoz-Darias, a Ramón y Cajal Fellow at the Institute of Astrophysics of the Canaries[Instituto de Astrofísica de Canarias] (ES), is trying to understand what makes black holes hungry. “I study systems called X-ray binaries,” he says, “where a normal star orbits a black hole at such close distance that the black hole steals material from the star.” But since both are rotating around each other, the material doesn’t fall directly into the black hole; instead, it forms an accretion disc around it. “Gas in the accretion disc gets really hot, up to ten million degrees, thus emitting highly energetic radiation like X-rays.”

    This doesn’t happen all the time though. “Most black holes are sleeping and they wake up every now and then,” Teo explains.“If there is little gas in the disc, it will just stay there orbiting the black hole. But when enough gas accumulates, it becomes hotter and friction increases; the gas then loses energy and spirals towards the black hole.” Not all the gas suffers that demise, though; sometimes it can leave the system via powerful winds and jets.

    When one of these systems becomes active, dedicated space telescopes will pick up the sudden burst of X-rays. Astronomers worldwide are notified about this and start collecting additional data from ground-based telescopes, quickly sharing their findings via The Astronomer’s Telegram. Teo constantly keeps an eye on this, as interesting targets can show up anytime. “Black holes don’t care about Saturdays, Sundays, or holidays,” he jokes. “In fact they tend to pick holidays!”

    Upon finding a suitable target, Teo triggers Target of Opportunity observations with various instruments, like the X-shooter spectrograph at ESO’s VLT.

    “X-shooter is probably the best instrument worldwide for this kind of science,” he says. “With it you are able to get a spectrum all the way from the ultraviolet to the near infrared in one go, and this is fantastic. It’s not only that you get a lot of data, but you get it simultaneously.” This is key with rapidly changing objects, as it allows astronomers to follow how they evolve at different colours without having to coordinate observations with separate instruments.

    Thanks to observations like these, Teo and his team could study in great detail the complex balance between gas accretion onto the black hole and gas being expelled outwards due to winds. They found that winds are present even when the system is asleep, and that when they are awake their activity can end prematurely when a lot of gas is removed.

    The most energetic explosions in the Universe

    When it comes to unpredictability, nothing beats gamma-ray bursts (GRBs) –– sudden flashes of high-energy gamma radiation. “GRBs are the brightest things known to science,” says Nial Tanvir, a professor at the University of Leicester (UK).

    “Some are produced when a massive star implodes at the end of its lifetime, leaving behind a neutron star or a black hole. Other GRBs are caused by the merger of two neutron stars. GRBs give us access to the most extreme physics that we know of in the Universe.”

    As opposed to comets and black holes feasting off closeby stars, which require astronomers to react within days, GRBs sometimes need to be observed minutes after they occur. “GRBs start out bright and decline in luminosity quickly,” Nial says. “So if you can get there early, there’s just so much more information that you can get with a shorter amount of telescope time. If you can get observations within minutes and then continue to monitor over a few hours, in some cases you see variability, which can tell you important things about the GRB and its environment.”

    To allow astronomers to react so quickly, ESO offers them a unique observing mechanism called “Rapid Response Mode”. When this mode is triggered, an alarm instantly goes off in the Paranal control room: the ongoing observations will be aborted –– if it’s safe to do so –– and the telescope will automatically slew towards the sky coordinates of the GRB. Unfortunately, this requires knowing the exact location of the GRB from the get go, which isn’t always the case.

    One of the most exciting events that Nial has studied was the first-ever detection of light from two merging neutron stars. On 17 August 2017 the LIGO and Virgo interferometers registered gravitational waves –– ripples in space-time –– passing through Earth. Two seconds later, the Fermi and INTEGRAL space telescopes detected a GRB coming from the same area of the sky.


    Both were the smoking-gun evidence of a kilonova: two neutron stars smashing against each other.

    As night fell in Chile, dozens of telescopes started to chase this unique event. “Neither the gravitational waves nor the gamma rays gave us a tremendously accurate localisation,” says Nial. So this was like looking for a needle in a haystack, scanning a large patch of the sky looking for a small dot that wasn’t there before. The Swope telescope at Las Campanas Observatory was the first one to locate the host galaxy: NGC4993, an elliptical galaxy about 140 million lightyears away.

    Five other teams found it independently during those hectic first couple of hours, including Nial’s group using ESO’s VISTA telescope [below].

    “You just did have that strong sense that you were sort of living through history, perhaps more so than anything else I’ve been involved with.” During the next few weeks, astronomers worldwide monitored the evolution of this object with pretty much every telescope they could, including 14 instruments from 7 ESO-related telescopes. “As the days went by this thing started to become redder and redder, just as predicted. The collision pulled very radioactive material out of the neutron stars, which then decayed to form a whole lot of elements heavier than iron like gold, platinum and uranium, whose origin had previously been quite mysterious.”

    It’s all about teamwork

    Observing these unpredictable events is only possible thanks to team spirit. In the case of the kilonova, for instance, astronomers barely had a couple of hours after sunset to observe it before it sank under the horizon. As Nial says, “The success of all of these campaigns really came down to the staff at the telescopes, who were doing their very best to squeeze in those observations in difficult circumstances.”

    But this is only part of the story, as good planning is also key. “ESO is not just Paranal or La Silla observatories,” explains Cyrielle. “It also has an amazing team at the User Support Department to help us prepare and adjust our observations, so that we make the best possible use of the instruments. When I was preparing observations of the interstellar comet 2I/Borisov, they helped me design unusual observations that spanned several months. Without them we could never have obtained such high-quality data to study an interstellar comet.”
    Note

    [1] Unlike other instruments, ESPRESSO isn’t physically attached to a Unit Telescope. The light from any UT, even all four of them, can be fed into the instrument.

    See the full article here .


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    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) 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”.

    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) 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,

    European Southern Observatory(EU) , Very Large Telescope 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. [/caption]

    ESO Very Large Telescope 4 lasers on Yepun (CL)

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    European Southern Observatory(EU) ExTrA telescopes at erro LaSilla at an altitude of 2400 metres.

     
  • richardmitnick 4:56 pm on June 4, 2021 Permalink | Reply
    Tags: "Stunning images and fantastic discoveries", , , , ESOblog (EU), , Ten years of ESO's VLT Survey Telescope   

    From ESOblog (EU): “Stunning images and fantastic discoveries” “Stunning images and fantastic discoveries””Stunning images and fantastic discoveries” 

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    Ten years of the VLT Survey Telescope

    Next week, the VLT Survey Telescope (VST) [below], located at ESO’s Paranal Observatory in the Chilean Atacama Desert, celebrates its tenth birthday. The anniversary marks ten years since the telescope’s “first light”, when it opened its eye to the sky and collected light for the first time. However, the story of the VST begins long before this point and proves to be an ultimate tale of triumph in the face of disaster… To find out more, we spoke to Massimo Capaccioli, principal investigator of the VST; Pietro Schipani, project manager during the telescope’s commissioning; Konrad Kuijken, principal investigator of the VST’s OmegaCAM instrument; and Enrichetta Iodice, principal investigator of one of VST’s science programmes.

    The skyline of Cerro Paranal is dominated by the four 8.2-metre telescopes that are part of ESO’s Very Large Telescope [below]. But these cyclopes share the mountain summit with smaller telescopes, including a 2.6-metre one: the VLT Survey Telescope (VST). Although VST takes its name from its larger neighbours, it serves a completely different purpose. Rather than scrutinising small patches of the sky in great detail, the VST constantly scans much wider areas of the sky, mapping and cataloging celestial sources, following the evolution of objects that change in time, and discovering the rare and unknown.

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    All four of the VLT’s Unit Telescopes can be seen in this image, as well as the VLT Survey Telescope (far right). Whereas the VLT is designed to examine small areas of the sky in tremendous detail, the VST surveys large swathes of the sky in a much shorter period of time, collecting a huge archive of data that can be used to find small, interesting objects, such as near-Earth asteroids, exoplanets, and distant quasars.
    Credit: A. Tudorica/ESO.

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    The first released VST image shows the spectacular star-forming region Messier 17, also known as the Omega Nebula or the Swan Nebula, as it has never been seen before. This vast region of gas, dust and hot young stars lies in the heart of the Milky Way in the constellation of Sagittarius (The Archer). The VST field of view is so large that the entire nebula, including its fainter outer parts, is captured — and retains its superb sharpness across the entire image. The data were processed using the Astro-WISE software system developed by E.A. Valentijn and collaborators at University of Groningen [Rijksuniversiteit Groningen] (NL) and elsewhere.
    Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: OmegaCen/Astro-WISE/Kapteyn Astronomical Institute University of Groningen [Rijksuniversiteit Groningen] (NL).

    “If you would like to have an idea of how things work in the Universe, you need to view a large number of objects or structures.”

    “To do this, you need dedicated instruments, with as wide a field of view as possible,” says Massimo Capaccioli, from the Italian National Institute for Astrophysics (INAF Italian National Institute for Astrophysics [Istituto Nazionale di Astrofisica] (IT)). The VST hosts only one instrument, OmegaCAM, an optical camera with a field of view so large you could fit four images of the full Moon in it.

    OmegaCAM detects the light captured by the VST, with such good image quality that it delivers crisp images with small, round stars from corner to corner.

    Astronomers find it useful to survey the skies because they can’t directly experiment with the objects they study, so they circumvent this by observing lots of them.

    Per aspera ad astra: through hardships to the stars

    The idea for the VST first came about in the 1990s, at the Astronomical Observatory of Capodimonte [Osservatorio Astronomico di Capodimonte] (IT) in Italy (now a part of INAF), which Capaccioli directed back then.

    “It looked like a crazy idea that a small institute like Capodimonte was proposing a telescope for the best observatory in the world!” says Pietro Schipani (INAF). “But you have to be brave sometimes”.

    The light-polluted Italian skies led the Capodimonte astronomers to seek a partnership with ESO, allowing the telescope to be built at ESO’s Paranal Observatory, which boasts some of the darkest and clearest skies on the planet. In 1998, a memorandum was signed between Massimo Capaccioli and the director general of ESO, giving the go-ahead for the project to begin.

    OmegaCAM was designed and built by a consortium from the Netherlands, Germany and Italy, and ESO manufactured the 268-megapixels array of detectors. The project was led by Konrad Kuijken, from Leiden University [Universiteit Leiden] (NL); an astronomer by trade, whose scientific interest –– measuring how dark matter bends light and distorts the shapes of galaxies –– inspired him to take on the project.

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    Image of the OmegaCAM under construction, the camera for the VLT Survey Telescope (VST) in the Chilean desert. The OmegaCAM will provide views of faint and rare objects for the Very Large Telescope to then examine, and work as a surveyor for trans-Neptunian objects, distant galaxy clusters, and other astronomical objects. It succeeds the present Wide Field Imager (WFI) at the 2.2-m MPG/ESO Telescope on La Silla [below]. Credit: ESO.

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    This raw image, straight from the OmegaCam instrument on the VST, was used together with many others to produce the iconic photo of the Carina Nebula (eso1250). The images taken with astronomical instruments are always in intensity scale: the colour information is obtained by taking exposures through different glass filters. The 32 individual 8-megapixel detectors are visible, separated by black gaps. In the final image, these are filled by combining images taken at slightly different positions. Long “bleeds”,caused by bright stars saturating the detector, are also visible.
    Credit: ESO.

    Work on the telescope progressed well until 2002, when disaster struck during the transport of the VST primary mirror to Chile. Capaccioli remembers this incident with despair: “Unfortunately, an accident involving the cargo during an intermediate stop over in Central America caused destruction of the beautiful primary mirror. It was literally reduced to crumbs, the largest astronomical mirror ever destroyed.”

    The whole project ground to a halt. The VST was built around its primary mirror and work was not able to continue until it was recast, causing a four-year delay and seriously damaging the morale of the team, leading to many engineers leaving the project.

    But the VST’s misfortune didn’t end there. “In terms of shipping, this project was clearly cursed!” says Kuijken.

    In 2009, the support system for the primary mirror was shipped to Chile. Alas, during transport seawater seeped into the box containing the mirror support, damaging it beyond repair. Schipani remembers opening the box and discovering the flood. “There were silica gel bags to prevent humidity… and they were floating in the water.” No one could have foreseen quite how humid the conditions in the box were going to end up!

    After another year’s delay, every part of the telescope finally reached Paranal. It was now ready for commissioning, the stage where astronomers and engineers work side-by-side, fine-tuning the telescope and camera to ensure they perform as expected.

    In particular, delivering perfectly crisp images was key. As Schipani says: “Sometimes I summarise my work by saying that I try to make the stars round and small. In Paranal the atmospheric conditions are fantastic, so all the defects of the machine that you are building will be perfectly seen on the image. So you must really take care of all the details.”

    Finally, the VST was ready for first light. This moment was eagerly awaited by Capaccioli, who recalls asking the team at Paranal to “call at any time, day or night, when the photons go through and produce something.” Kuijken adds, “It was one of the most exciting times in my career, for sure.”

    First light at last

    In spite of all the setbacks, the VST had done it, and the first images proved it was working beautifully. Although the construction process was fraught with difficulties, the scientists and engineers working on the project found that there had been some silver linings to the long wait for the VST.

    “We have learned that if you have to redo something, it often turns into an opportunity to improve it,” says Capaccioli. “If you have a second chance, the prototype will be better. Usually with telescopes, you make it once and then you don’t repeat it. In the case of the VST disasters, we used this as an opportunity.”

    Scientists and engineers often approach these complex problems from opposing points of view. “Sometimes the best solution engineering wise is not the best solution science wise,” says Kuijken. “To resolve this you have to understand a little bit from both sides of the argument.” Teamwork was thus key to the project reaching its completion.

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    The second released VST image, showing the Omega Centauri globular cluster, an agglomeration of hundreds of thousands stars. The sharp stars in this view demonstrate the superb image quality of the telescope and its camera. Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: A. Grado, L. Limatola/INAF-Capodimonte Observatory.

    While working round the clock in such a remote location is certainly challenging, the magical atmosphere of Paranal left the team with some unforgettable memories. “Walking around between these telescopes on a beautiful starry night, it’s like being in a temple,” Kuijken says. This silence was often broken by the excitement of the astronomers, as Schipani remembers: “Paranal is a quiet place but during the nights you could hear on the platform people screaming and crying ‘Oh, fantastic!’ as they made observations.”

    Iodice concurs: “There in Paranal it is like a big family,” she says. “You can interact with the engineers, astronomers and telescope operators all at the same levels, and each of us there has a particular knowledge and experience. Sharing this is fantastic. I always enjoyed the environment and the atmosphere. I feel I work better there.”

    Now in its tenth year, has the VST achieved the goals set out so long ago at the start of its journey? Iodice, who is the principal investigator of the VST Early-type GAlaxy Survey, certainly thinks so. The survey she leads initially concentrated on the brightest galaxies in the nearby Universe, but has more recently switched focus to fainter structures, such as ultra-diffuse galaxies — objects as large as the Milky Way but hundreds of times fainter, whose origin is still unknown. “We detected these ultra-diffuse galaxies by chance in our VST surveys. The results we achieved with the VST exceeded our expectations,” she says.

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    The wide-field optical camera on ESO’s VLT Survey Telescope (VST) — has captured the spectacular Orion Nebula and its associated cluster of young stars in great detail, producing this beautiful new image. This famous object, the birthplace of many massive stars, is one of the closest stellar nurseries, at a distance of about 1350 light-years. Credit: G. Beccari/ESO.

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    The VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile has captured this beautifully detailed image of the galaxy Messier 33, often called the Triangulum Galaxy. This nearby spiral, the second closest large galaxy to our own galaxy, the Milky Way, is packed with bright star clusters, and clouds of gas and dust. This picture is amongst the most detailed wide-field views of this object ever taken and shows the many glowing red gas clouds in the spiral arms with particular clarity. Credit: ESO.

    The VST has helped to unravel mysteries in other corners of the Universe: it has imaged stellar nurseries in our own galaxy, mapped the distribution of dark matter in the Universe –– what first drove Kuijken into leading OmegaCAM –– and even captured the violent collision of two neutron stars. As one of the best optical survey telescopes operating in the Southern Hemisphere, the VST continues to deliver stunning images of the Universe.

    The VST holds a special place in the hearts of all who worked on it, and refused to give up on it when the going got tough. “I am happy and proud of the VST as a father would be of a very successful son who has had a difficult childhood,” says Capaccioli. Schipani adds, “I have worked on the VST for a period of about ten years. It’s not like a normal project, it is really a part of me.”

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO (EU) in Social Media-

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    ESO Bloc Icon
    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) 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”.

    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) 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,

    European Southern Observatory(EU) , Very Large Telescope 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. [/caption]

    ESO Very Large Telescope 4 lasers on Yepun (CL)

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    European Southern Observatory(EU) ExTrA telescopes at erro LaSilla at an altitude of 2400 metres.

     
  • richardmitnick 4:48 pm on May 21, 2021 Permalink | Reply
    Tags: "Is there life on Earth?", , , , ESOblog (EU), From ESOblog (EU),   

    From ESOblog (EU): “Is there life on Earth?” 

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    21 May 2021
    Science@ESO

    How observing lunar eclipses helps us search for life in other planets.

    Astronomers have discovered thousands of exoplanets –– planets orbiting stars other than the Sun. When looking for the chemical fingerprints that life might have left in the atmospheres of these worlds, astronomers have turned to an unlikely ally: the Moon. Lunar eclipses like the one we will see on May 26 allow us to study the Earth’s atmosphere in the same way we do with exoplanets, which will help us recognise the signatures of life when we eventually find them.

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    Juan Carlos Muñoz Mateos

    A planet where it rains iron. Another one where a year lasts only 18 hours. One that orbits two suns. You would be forgiven for thinking that these alien worlds belong to a science-fiction show, but these are very real planets that astronomers have actually found around other stars.

    The first of these strange new worlds were discovered in 1992 by Aleksander Wolszczan and Dale Frail, who found two planets orbiting a pulsar, the rapidly rotating corpse of a massive star; a third planet was confirmed shortly afterwards. Three years later Michel Mayor and Didier Queloz found the first planet orbiting a Sun-like star, a discovery that earned them the Nobel Prize in Physics in 2019. At the time of writing, the number of confirmed exoplanets is 4383, but this figure might be outdated by the time you get to read this.

    Astronomers are keen on studying the atmospheres of these worlds, searching for biomarkers –– chemical signatures that might be tell-tale signs of life. But how do they do this?

    Observing stellar blinks

    When an exoplanet crosses in front of its parent star, as seen from Earth, it blocks part of the starlight, causing a small but measurable dip in the star’s brightness. These so-called transits can be found by observing the same patches of the sky over and over, looking for stars that periodically blink.


    Transit of an exoplanet (Europe to the Stars Clip)
    This artist´s impression shows how the intensity of the light of a star varies when a planet transits its disc.Credit: L. Calçada/ESO.

    When the light of a star passes through the atmosphere of a transiting exoplanet it is partially scattered and absorbed. Haze scatters blue colours more efficiently than red ones, making starlight somewhat redder –– just like Earth’s atmosphere makes the Sun look red at sunrise or sunset. In addition to that, different atoms and molecules in the atmosphere of an exoplanet will absorb very specific colours. Using spectroscopy, a technique that decomposes light into its constituents colours or wavelengths, it is thus possible to analyse the fingerprint left by an exoplanet’s atmosphere on the light of the host star.

    3
    As WASP-19b passes in front of its parent star, some of the starlight passes through the planet’s atmosphere and leaves subtle fingerprints in the light that eventually reaches Earth. By using the FORS2 instrument on the Very Large Telescope the team was able to carefully analyse this light and deduce that the atmosphere contained small amounts of titanium oxide, water and traces of sodium, alongside a strongly scattering global haze. Credit: M. Kornmesser/ESO.

    Molecules like ozone or oxygen, among others, are often called “biomarkers”: when found in the right amounts they could signal the presence of life. But what does the spectrum of an inhabited planet actually look like? Well, so far we only know one such planet: Earth. So how can we observe the Earth as if it was an exoplanet? By using the Moon as a mirror.

    Mirror, mirror…

    In a lunar eclipse, the Sun, Earth and Moon are aligned, and the Moon moves into the Earth’s shadow. If the Earth didn’t have an atmosphere the Moon would appear pitch black. But Earth’s atmosphere redirects sunlight towards the Moon, and since blue light is scattered away more easily than red light, which passes through almost unimpeded, the Moon is bathed with red sunlight. If you stood on the Moon during a lunar eclipse, the Earth would appear surrounded by a glowing ring of light: you would be witnessing infinite sunrises and sunsets all over the planet.

    By analysing the sunlight that illuminates the eclipsed Moon, after having passed through Earth’s atmosphere, we can look for the chemical fingerprints of different atoms and molecules, just like we do with transiting exoplanets.

    4
    This image shows the Moon at various stages during a total lunar eclipse in January 2018. The Moon turns red during a lunar eclipse because it is illuminated by light that has passed through the Earth’s atmosphere. This reddish colour has therefore led to a lunar eclipse being known as a “Blood Moon”. Credit: P. Horálek/ESO.

    Spectroscopic observations of lunar eclipses are over a century old, but detailed studies are surprisingly recent. In 2008, a team of astronomers led by Enric Pallé used telescopes at the Roque de los Muchachos Observatory | Instituto de Astrofísica de Canarias • IAC(ES) in La Palma, Spain, to observe a lunar eclipse. Their results clearly indicate the presence of ozone, oxygen, water vapour, methane and carbon dioxide, in the relative amounts one expects to find in a planet that harbours life. Another group led by Luc Arnold performed similar observations of another lunar eclipse in 2010. They used the UVES and HARPS spectrogrographs at ESO’s Very Large Telescope [below] and 3.6-metre telescope [below] in Chile, respectively, and found ozone, oxygen and water vapour. Even the NASA/ESA Hubble Space Telescope has had a go at this: in 2019, Allison Youngblood and her team performed the first-ever space-based observations of a lunar eclipse, aiming to find ultraviolet spectral features of ozone that are harder to detect from the ground.

    But even when it’s not eclipsed, the Moon still helps us look for signs of life on Earth. If you have ever looked carefully at the thin crescent Moon you may have noticed that the dark portion is actually faintly lit. This is called earthshine, and it’s sunlight reflected off the Earth towards the Moon, and then back to us. This reflected sunlight also carries the chemical signature of the various molecules present in our atmosphere.

    In 2011, a team led by ESO astronomer Michael Sterzik used ESO’s FORS2 instrument at the VLT to observe earthshine: their measurements were sensitive to the cloud coverage, the presence of oceans, and even vegetation, thus rediscovering life on Earth.

    In a similar vein, astronomers have been able to study the spectra of light reflected off exoplanets. In 2015, a group led by Jorge Martins used ESO’s HARPS spectrograph to detect light bouncing off 51 Pegasi b, the Nobel-winning planet that Mayor and Queloz discovered back in 1995.

    While this so-called “hot Jupiter” is most certainly lifeless, this technique is very promising to study the atmospheres of other exoplanets.

    Onwards and upwards

    The exoplanets whose atmospheres have been characterised so far tend to be gas giants, similar to Jupiter. Small rocky worlds like Earth are much harder to study: their atmospheres are so thin that they only block a minuscule fraction of their host star’s light. Studying them in reflected light isn’t any easier, as they are drowned in the glare of their star.

    Analysing the atmospheres of these smaller worlds requires the immense light-collecting capabilities of the next generation of gigantic telescopes, such as ESO’s Extremely Large Telescope. With its 39-metre mirror and an array of sophisticated instruments, the ELT will offer new ways to better understand exoplanets.

    But if you are bewildered by this complex technology don’t worry: just look up to the Moon, and remember that hidden in the red glow of a lunar eclipse or the faint earthshine are the chemical clues that betray the presence of life here on Earth.

    See the full article here .


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    Please help promote STEM in your local schools.

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    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) 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”.

    European Southern Observatory(EU) , Very Large Telescope 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. [/caption]

    ESO Very Large Telescope 4 lasers on Yepun (CL)

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    European Southern Observatory(EU) ExTrA telescopes at erro LaSilla at an altitude of 2400 metres.

     
  • richardmitnick 10:43 am on May 7, 2021 Permalink | Reply
    Tags: "Meet our PhD students", , , , ESOblog (EU),   

    From ESOblog (EU): “Meet our PhD students” 

    ESO 50 Large

    From ESOblog (EU)

    5.7.21
    People@ESO

    1
    How studying at ESO can open your doors to the stars.

    Besides building and operating world-class telescopes, ESO trains the next generation of astronomers via its Studentship Programme. By bringing together astronomers, engineers and other professionals from multiple countries, ESO provides a diverse environment where students can develop a unique skill set. We have talked to five ESO PhD students to learn about their experience working in such a nurturing atmosphere.

    “One of the high points of being at ESO is seeing the Extremely Large Telescope [below] being built right in front of you!” Aishwarya Girdhar, a PhD student at ESO in Garching, loves witnessing first-hand the development of what will soon be the largest visible/infrared telescope in the world. Key components of the ELT and other telescopes are assembled and tested at ESO’s integration hall in Garching. “Walking by the integration hall every time you can see something new being built and assembled. It is exciting to see what the ELT will bring for us in the future!”

    This combination of science and technology makes astronomy uniquely multidisciplinary, with researchers and engineers working side by side to design, build and operate increasingly sophisticated telescopes and instruments. But how can PhD students hone their skills on modern astronomical instrumentation?

    Students who are already enrolled in a university PhD programme can spend one or two years at the ESO offices in Germany or Chile, co-supervised by an ESO staff astronomer together with their supervisor at their home university. Students can also do their PhD at ESO via the International MPG Research Schools (IMPRS), of which ESO is a partner. We have talked to five ESO PhD students to learn about their research and what they enjoy the most about their experience at ESO.

    From distant galaxies to nearby comets

    3
    Aishwarya stands on the catwalk of the Danish 1.54-metre telescope [below] at La Silla Observatory [below]. In the background, from left to right, we can spot the MPG/ESO 2.2-metre telescope, the ESO 1-metre Schmidt telescope, the New Technology Telescope, and the ESO 3.6-metre telescope.
    Credit: A. Girdhar.

    Aishwarya joined ESO’s PhD programme via the IMPRS. She studies supermassive black holes lurking at the centre of galaxies.

    “Some of these black holes are in an active state, which means they are accreting the gas around them and expelling radiation and gas as outflows. These outflows can interact with the gas in the galaxy and cause large-scale disturbances. The aim of my PhD thesis is to understand how these outflows affect star formation in their host galaxies.”

    To investigate these so-called active galactic nuclei (AGN), Aishwarya uses various instruments at ESO’s Very Large Telescope (VLT) [below] such as MUSE, which allows her to map the properties and motion of the gas in these galaxies.

    4
    Both Garching and Santiago are within short distance of various hills and mountains, perfect for hiking lovers like Stephen, seen here close to the German town of Bad Kohlgrub.
    Credit: S. Molyneux.

    Stephen Molyneux, a PhD student at Liverpool John Moores University (UK), is also trying to unravel the connection between AGN and their host galaxies during his ESO studentship in Garching. “In some galaxies we see radio jets that seem to be driven by the AGN, and they could interact with the gas in the host galaxy. This can lead to galactic outflows and impact on the star formation and gas content of the galaxy, perhaps even removing gas from the galaxy itself.”

    5
    Besides Paranal, Sebastián has also visited La Silla Observatory. Here he stands at sunset on the catwalk of the ESO 1-metre telescope, in front of some of La Silla’s telescopes, such as the three spherical domes of the ExTrA telescopes in the foreground. Credit: S. Zúñiga.

    Closer to home, in our own galaxy, Sebastián Zúñiga is studying the complex dynamics of multiple stars orbiting each other. “For my ongoing project I observed a quadruple system of stars using the PIONIER instrument on the VLTI at Paranal Observatory,” he says, referring to ESO’s VLT Interferometer, which combines the light gathered by several of the VLT’s telescopes to discern incredibly small details. “With these observations I was looking to resolve different details about the system, which is composed of two binary star pairs orbiting one another.” Sebastián is now back at the University of Valparaíso [Universidad de Valparaíso] (CL) after completing his studentship at ESO in Santiago.

    6

    At the Príncipe Felipe Science Museum in Valencia (Spain), Jessica poses in front of a picture of the Gum 29 nebula, where young stars are being born out of the surrounding gas.
    Credit: J. Erkal.

    Jessica Erkal, a PhD student at University College Dublin (IE), is currently spending one year at ESO in Garching studying how stars form. “My focus is on protostellar jets, which are large columns of material that move away from the star at speeds as high as a few hundred km/s!” she explains. “By examining the size and shape of the jet and how it moves through space we can try to learn how the jet is launched and formed, and if this has an effect on the disk where planets might form.” For her research, Jessica is using data from the X-shooter spectrograph on the VLT. “I’m looking at a sample of almost 200 stars, examining an infrared helium line which tells us if there is material accreting onto the star or moving away from it.”

    7
    At sunset, Youssef took this family portrait of the telescopes atop Cerro Paranal. The four 8-metre telescopes of the VLT have already opened their domes, ready to observe the night sky. Three of the four smaller Auxiliary Telescopes can also be seen, as well as the VLT Survey Telescope in the background.
    Credit: Y. Moulane.

    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 (EU) in Social Media-

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    ESO (EU) 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”.

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

     
  • richardmitnick 12:51 am on April 25, 2021 Permalink | Reply
    Tags: "Paranal Perspectives", , , , , ESOblog (EU), Gerd Hüdepohl (atacamaphoto.com), People@ESO   

    From ESOblog (EU): “Paranal Perspectives” 

    ESO 50 Large

    From ESOblog (EU)

    23 April 2021
    People@ESO

    1
    Gerhard Hüdepohl

    Home to ESO’s Very Large Telescope (VLT), Paranal Observatory in Chile’s Atacama Desert has been at the forefront of astronomical research since its inauguration in 1999.

    Over the years, it has earned a reputation as one of the best observing sites in the world. To find out more about its evolution, we spoke to Gerhard Hüdepohl, who documented his time as an engineer at Paranal through some spectacular photography.

    “I still have it here, on my shelf!” Gerhard holds up his Praktica, a purely mechanical reflex camera that he was given by his father at the age of fifteen. “It still sort of works. I wouldn’t bet that it still exposes correctly, but it’s a nice memory to have.”

    When his father bought himself a new camera, giving Gerhard his old Praktica, it was the start of a life-long passion. “From there on I was hooked,” he says. “From my father, who developed his own film at home, and with friends, I continued to learn and improve. It’s been a never-ending process ever since.”

    Gerhard took photographs whenever he could. After studying electronic engineering at university, he worked as a commissioning engineer in several countries, including China, Australia, and South Korea, providing plenty of chances for inspiration. His first time in Chile, however, was as a tourist. It was on this trip that he caught his first glimpse of ESO, in the form of La Silla — the oldest of ESO’s observatories.

    “I was in Chile in ’94”, he recalls, “on a bus to the north. From the window I saw La Silla, and I remember thinking, ‘wow, that’s somewhere I would like to work.’ These huge telescopes that were used to understand the secrets of the stars really caught my attention.”

    Construction of the VLT at ESO’s Paranal Observatory, 500 kilometres north of La Silla, began in 1991, but it wasn’t until the majority of concrete and steel work was complete that opportunities arose for electronic engineers. From Malaysia, where he was working at the time, Gerhard applied to work for ESO.

    “Although I always had an interest in the Universe, I think I was more interested in these giant, perfect machines than in astronomy. These telescopes have the weight and size of a ship, but have to work to a precision of within a few thousandths of a milimetre. I find that fascinating”. [1]

    The early days of Paranal

    “I joined ESO in 1995, and in my first years I was working as part of the Assembly, Integration and Verification team of the VLT,” says Gerhard. “The priority was to reach the first light on schedule.”

    At a time when the telescopes were still under construction, the atmosphere at Paranal was unique. The Residencia — the futuristic-looking lodge where ESO staff now reside when working on-site — had not been built yet, so everyone was living in the adjacent basecamp. And in this early stage of construction, priorities could change at short notice.

    2
    The long, facade opens towards the Pacific Ocean and provides a great view of the colourful sunset. The terrace in the middle is part of the Cantine Area but can only be used when the wind is not too strong. Credit: Gerd Hüdepohl (atacamaphoto.com).

    “Living and working together, in such an isolated location, really welds the team together. You depend on each other, and there’s no escape. It’s a little bit like being on a ship in the middle of the ocean — if you don’t row together, the ship won’t go anywhere.”

    One of the most important milestones for Paranal was the first light of the VLT’s Unit Telescope 1, Antu, in 1998. Unsurprisingly, this was one of Gerhard’s most memorable moments from his time at the observatory.

    “Late one evening, after many months of assembling and testing the telescope, we opened the large observing slit doors of Antu’s dome for the first time, and pointed the telescope to the stars.

    This huge telescope moved silently around its axes to the sky. That moment I will never forget.”

    3
    The almost-finished dome of UT1 (Antu) stands next to the empty steel frame of UT2 (Kueyen). Credit: G.Hüdepohl (atacamaphoto.com)/ESO.

    4
    Engineers inside the dome of UT3 (Melipal) watch carefully as a crane lifts down the top ring of the telescope. Credit: G.Hüdepohl (atacamaphoto.com)/ESO.

    5
    This image was taken when the UT4 telescope (Yepun) was still under construction. The golden evening sky can be seen through the empty skeleton of the dome. Cerro Armazones, home of the future Extremely Large Telescope, can be seen in the horizon. Credit:
    G.Hüdepohl (atacamaphoto.com)/ESO.

    La Residencia

    Inaugurated in 2002, La Residencia at ESO’s Paranal Observatory provides a welcome retreat from the harsh environment of the Atacama Desert. When you work in one of the driest places on Earth, the humidity provided by the oasis under the Residencia’s dome is a much-needed relief.

    “It was really nice to have a permanent room there,” says Gerhard. “As well as a gym and a swimming pool!”

    The Residencia has also welcomed guests beyond the engineers and astronomers working on site. Its exterior was featured in the 2008 James Bond film, Quantum of Solace.

    Gerhard was at Paranal during the filming, and had the fortunate opportunity to be involved in some behind-the-scenes work. “Below Paranal there is a small airstrip which was used in a scene, and they required some planes for decoration. At the time I had a pilot’s license, so I flew a small plane in from Antofagasta, which appears in the movie for a few seconds!

    7
    This marvellous aerial photograph of the home of ESO’s Very Large Telescope (VLT), fully demonstrates the superb quality of the observing site. In the foreground we see the Paranal Observatory, located at an altitude of 2,600 metres on mount Paranal in Chile. In the background we can see the snow-capped, 6,720 meter-high volcano Llullaillaco, located a mind-boggling 190 km further East on the Argentinean border. This image is a testimony of the magnificent quality of the air and the ideal conditions for observing at this remote site.

    Clearly visible in the image are the domes of the four giant 8.2-metre Unit Telescopes of the VLT, with the Control Building, where astronomers carry out the observations, in the foreground. Taken several years ago, this photograph does not show the Auxiliary Telescopes nor the dome of the soon to come VST Survey Telescope. Credit: /G.Hüdepohl (atacamaphoto.com) ESO.

    Different views of Paranal

    Gerhard’s pilot’s license came in handy on more occasions than the filming of Quantum of Solace. Several of his Paranal photographs, many of which can be found on the ESO image archive, were taken from the air.

    “One of my favourite photos, a very old one, shows Paranal in front of a snow-covered Llullaillaco”. The world’s highest historically active volcano, Llullaillaco, lies on the border between Chile and Argentina. On clear days, it can be seen from ESO’s Paranal Observatory.

    “There was a day when I happened to fly, when it had recently snowed, and when the skies were very clear. I got this picture, taken on film. I’ve tried several times to repeat this picture on digital, but could never get it exactly right.”

    “But I think my favourite photo is one I took with a drone, between the four laser beams of Yepun,” he says, referring to the VLT’s Unit Telescope 4. “It took quite some preparation, and several attempts, to get the image I had in mind.”

    7
    Twinkling stars are far more desirable to poets and romantics than to astronomers. Even in the near-pristine seeing conditions over Chile, home to ESO’s fleet of world-class telescopes, turbulence in Earth’s atmosphere causes stars to twinkle, blurring our view of the night sky.

    These four laser beams are specially designed to combat this turbulence. The intense orange beams dominating this image originate from the 4 Laser Guide Star Facility, a state-of-the-art component of the Adaptive Optics Facility of ESO’s Very Large Telescope (VLT). Each beam is some 4000 times more powerful than a standard laser pointer! Each creates an artificial guide star by exciting sodium atoms high in the Earth’s upper atmosphere and causing them to glow.

    Creating artificial guide stars allows astronomers to measure and correct for atmospheric distortion, by adjusting and calibrating the settings of their observing equipment to be as accurate as possible for that particular area of sky. This gives the VLT a crystal-clear view of the cosmos, so it can capture the wonders of the Universe in stunning detail.

    This amazing capture was taken using a drone flown over the VLT by ESO Photo Ambassador Gerhard Hüdepohl. Credit: G. Hüdepohl (atacamaphoto.com)ESO.

    These lasers create four artificial “stars” high up in the atmosphere, which are then used to measure and correct the atmospheric turbulence, allowing the telescope to capture crisp images. To take this stunning shot, Gerhard had only a time slot of around ten minutes when it was dark enough to see the lasers, yet light enough for the surrounding desert to be visible. After many attempts, Gerhard captured this spectacular image, which was featured in the National Geographic magazine. “For a photographer, this is something like the Oscars!”

    What’s next for Paranal?

    Another memorable moment from my time at ESO was during 2019, my last year”, Gerhard describes. “I was able to follow the first part of the construction of the ELT. At one moment, I realised that this stage of construction I was seeing was roughly the same as that of Paranal, when I first started working there. For me, it closed a cycle.

    8
    The first evening of the new year was beckoned in by a spectacular supermoon, rising up from behind the majestic Cerro Armazones mountain in Chile. A supermoon like this is a magnificent, albeit relatively frequent, occurrence which takes place when a full moon coincides with the point in the lunar orbit that is closest to Earth, its diameter appearing about 14% larger in the sky.

    The road zigzagging up Cerro Armazones appears to lead directly to the Moon itself — truly making it a road to the stars. By 2024, the “world’s biggest eye on the sky” will rest on top of this mountain, as its peak will be home to the Extremely Large Telescope. At an altitude of 3046 metres, Cerro Armazones provides a spectacular environment for astronomical observations, in particular because it receives 320 clear nights per year.

    This photo was captured by ESO Photo Ambassador Gerhard Hüdepohl. He walked two kilometres from ESO’s nearby Paranal Observatory into the Atacama Desert to find the right position to take this photo. Beforehand, he had calculated the path the Moon would take to know the right time and place for this extraordinary shot. Credit: G.Hüdepohl (atacamaphoto.com)/ESO.

    At Cerro Armazones, just 25 kilometres from Paranal, ESO is building the Extremely Large Telescope (ELT).

    As the largest infrared and visible light telescope in the world, the ELT will be revolutionary for astronomy. However, it is by no means the end of Paranal’s story. An exciting host of upcoming instruments, as well as upgrades to existing infrastructure, will open up new windows to continue studying the universe from Paranal. Moreover, the ELT will be operated from Paranal as well.

    Extremely large astronomy
    9
    The era of extremely large telescopes is beginning — and it will revolutionise our understanding of the Universe. ESO’s Extremely Large Telescope (ELT) is currently under construction in the remote Chilean Atacama Desert; this groundbreaking telescope alone will collect more light than over 200 NASA/ESA Hubble Space Telescopes.

    As the name suggests, such telescopes are truly colossal. The largest primary mirrors — by which a telescope collects light — currently in operation at all of ESO’s sites are the 8.2-metre-diameter mirrors in the four Unit Telescopes comprising the Very Large Telescope (VLT). The ELT will dwarf the already impressive VLT with its vast mirror at 39 metres in diameter! However, constructing a single, science-quality mirror of such a size is simply not possible — the ELT’s primary mirror will, in fact, be a complex honeycomb arrangement of 798 tessellated hexagonal 1.4-metre mirrors.

    Finding a suitable place for such a structure was also no easy task. As well as requiring the dry and light-pollution-free conditions at a high altitude necessary for successful astronomy, the ELT needed a huge space on which to spread its foundations. As such a location was not available, it was created! The complex journey of the ELT’s construction began by flattening the top of the Cerro Armazones mountain in Chile, taking 18 metres off its full height. That site is now covered by a web of foundations — as seen in this image. Credit: G. Hüdepohl/ESO.

    Note

    [1] The movable structure of each VLT Unit Telescope weighs about 430 tonnes and is so well-balanced and well-oiled that it can be moved by hand.

    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 (EU) in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO (EU) 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”.

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

     
  • richardmitnick 3:15 pm on April 9, 2021 Permalink | Reply
    Tags: "A 40-year-long mystery- heavy elements unveil the origin of the giant Leo Ring", , , , ESOblog (EU),   

    From ESOblog (EU): “A 40-year-long mystery- heavy elements unveil the origin of the giant Leo Ring” 

    ESO 50 Large

    From ESOblog (EU)

    1
    Not all spiral galaxies have to be picture-perfect to be striking. Messier 96, also known as NGC 3368, is a case in point: its core is displaced from the centre, its gas and dust are distributed asymmetrically and its spiral arms are ill-defined. But this portrait, taken with the FORS1 instrument on ESO’s Very Large Telescope, shows that imperfection is beauty in Messier 96.

    The galaxy’s core is compact but glowing, and the dark dust lanes around it move in a delicate swirl towards the nucleus. And the spiral arms, patchy rings of young blue stars, are like necklaces of blue pearls.

    Messier 96 lies in the constellation of Leo (The Lion). It is the largest galaxy in the Leo I group of galaxies; including its outermost spiral arms, it spans some 100 000 light-years in diameter — about the size of our Milky Way. Its graceful imperfections likely result from the gravitational pull of other members in the group, or are perhaps due to past galactic encounters.

    A multitude of background galaxies peers through the dusty spiral. Perhaps the most striking of these objects is an edge-on galaxy that — because of a chance alignment — appears to interrupt the outermost spiral arm to the upper left of Messier 96’s core.

    This image was processed by ESO using the observational data found by Oleg Maliy from Ukraine, who participated in ESO’s Hidden Treasures 2010 astrophotography competition [1], organised in October–November 2010, for everyone who enjoys making beautiful images of the night sky using astronomical data obtained with professional telescopes. The image was made with data taken at visible and infrared wavelengths through B, V, and I filters.
    Notes

    [1] ESO’s Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO’s vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. To find out more about Hidden Treasures, visit http://www.eso.org/public/outreach/hiddentreasures/.

    Credit: ESO/Oleg Maliy9 April 2021, Science@ESO

    Nearly 40 years ago, astronomers made a serendipitous discovery when they pointed a radio telescope at an “empty” patch of sky in the Leo constellation: a giant cloud of gas, massive enough to form a galaxy but unlike anything seen before. This started the decades-long quest to discover the origin of this gigantic structure, known as the Leo Ring. Astronomers first theorised that it was a remnant leftover from when the first stars formed within this group of galaxies. Now research using the MUSE instrument on ESO’s Very Large Telescope (VLT) has provided a definite answer to the question of the Leo Ring’s origin.

    European Southern Observatory(EU) , Very Large Telescope 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.

    In 1983, a team of astronomers led by PhD student Stephen E. Schneider was aiming to measure the properties of a distant galaxy and needed a “blank sky” reference measurement. Pointing the US Arecibo radio telescope at what they thought was an unremarkable patch of the sky, they found it was actually populated with cold hydrogen gas, revealing a giant gas cloud six times larger in diameter than the Milky Way. It was named the Leo Ring after its shape and for lying in the direction of the Leo constellation in the sky.

    The discovery of such a large gas cloud, and the lack of any stars detected in the ring, raised questions on how galaxies form and evolve. A gas cloud of this size should have collapsed under gravity to become one or more galaxies containing many stars.

    If the gas forming this structure had never been part of a galaxy, could the Leo Ring be an ancient cloud of gas left over from billions of years ago when galaxies were still forming? Or perhaps the gas was part of a galaxy, but it was stripped away from it and expanded to form the Leo Ring? However, even in the latter case, we would still expect to see some stars, either left over from a galaxy or created in the violent process of gas expansion.

    Now, nearly 40 years after its discovery, a new team of astronomers led by Edvige Corbelli from Arcetri Astrophysical Observatory, National Institute for Astrophysics (INAF) in Italy have tackled these questions conclusively.

    Stars are the key to determining the history of the Leo Ring. “The only way to solve the mystery of the Leo Ring’s origins is to measure the amount of heavy elements dispersed in the hydrogen gas,” explains Corbelli. “These elements are created by stars and, if found in large amounts, they could give a clear signal that the gas is not primordial.”

    The Leo Ring was widely believed to be a primordial cloud of gas, containing only the lightest elements — hydrogen, helium and a trace amount of lithium — that were created in the Big Bang, with no stars. Then in 2009, a team led by David Thilker of the John Hopkins University (US) were studying the first ultraviolet (UV) observation of Messier 96, when they made a serendipitous discovery. On noticing that the Leo Ring was visible at the edge of their image, they were able to identify clumps shining brightly in the UV that were possibly associated with the ring and could signal the presence of massive stars. This challenged the then-held theory that the ring lacked stars. However, astronomers could still not say for certain whether stars were forming in the Leo Ring, or whether they were picking up signatures of stars much further away in the background.

    The search was on to find stars born within the Leo Ring, young and massive enough to light up the heavy elements in the surrounding gas. These stars might be so faint and sparse that the hot regions around them might have escaped detection for decades — detecting them would require a powerful instrument and telescope, such as the MUSE instrument on ESO’s VLT. Giovanni Cresci, who is also from INAF and was involved in the research recently published in The Astrophysical Journal Letters, said, “We were already using MUSE and other instruments at ESO to study nearby and distant galaxies. So, when Edvige told us of the Leo Ring mystery, we realised that MUSE would be ideal to finally provide an answer about the origin of this huge structure”.

    “For the first time within the ring, we have detected nebulae ionised by rare and isolated massive stars, 30–40 times more massive than our Sun.”

    By using MUSE, the astronomers looked at three clumps of hydrogen gas where UV radiation had been found. “For the first time within the ring, we have detected nebulae ionised by rare and isolated massive stars, 30–40 times more massive than our Sun,” says Corbelli. The presence of these stars and nebulae meant the team was able to measure the abundance of heavy elements within the nebulae, which proved the stars were in the Leo Ring and suggested the gas was not primordial.

    Filippo Mannucci, an astronomer at INAF-Arcetri, says, “We have been measuring chemical abundances in galaxies for many years, but we had never applied our methods to such a special object.” During their lifetimes, massive stars produce heavier and heavier elements until they reach iron, run out of fuel and explode as supernovae. Cresci expands, “Our observations allowed us to see for the first time these faint and rare little spots of gas ionised by the few young, massive stars in the ring.”

    2
    This is an optical image of galaxies in the Messier 96 group, with contours of the gas in the Leo Ring from the Arecibo radio telescope in blue and from the Very Large Array in magenta (taken from Schneider et al 1986). White squares indicate the locations Corbelli’s team observed with the VLT’s MUSE instrument, with the boxes showing the more detailed MUSE observations. Here, the labels mark the locations of the detected nebular regions powered by massive stars. Credit:ESO/E. Corbelli, Sloan Digital Sky Survey, Arecibo/VLA/Schneider.

    The team found a large abundance of heavy elements throughout the structure. “To pollute the ring with so many heavy elements, we would need many more stars than we observed,” says Corbelli. The lack of stars then raises more questions: how were these heavy elements dispersed throughout the structure?

    Without the presence of many additional stars, the gas must have been enriched with these elements in a place where a lot of older stars are found, for example in an older galaxy.

    “This means the ring is not a leftover gas cloud sitting around from the time when other galaxies were forming. The gas has been enriched by heavy elements in a galaxy disc, and later removed by the gravitational pull of a galaxy-galaxy encounter before forming the ring,” explains Corbelli.

    The answer of how the Leo Ring came to be is through the collision of two galaxies. This massive energetic event spanning millions of years had such a strong gravitational force that gas, and heavy elements, were pulled from within a galaxy and dispersed throughout space. Previous work led by Leo Michel-Dansac at the University of Lyon in 2010 using computer simulations suggested that two galaxies, Messier 96 and NGC 3384, may have collided to form the Leo Ring. Corbelli’s team have now confirmed that a close encounter between galaxies is the most likely scenario for the formation of this mysterious object.

    This climactic solution to the Leo Ring mystery came through decades worth of research and innovation. After nearly 40 years, we finally have closure on its origin and can appreciate how existing theories were challenged and changed in the light of new evidence. However, the Leo Ring has yet to yield all of its secrets. Corbelli concludes, “Now that we have established that the gas has been removed from a galaxy during a galaxy-galaxy encounter, the big question for the future is: why did the ring not manage to form more stars?”

    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 (EU) in Social Media-

    Facebook

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    ESO Bloc Icon

    ESO (EU) 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.

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

    ESO VLT 4 lasers on Yepun.

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light at an elevation of 2,635 metres (8,645 ft) above sea level.

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

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

    ESO ELT 39 meter telescope 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/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev .

     
  • richardmitnick 3:48 pm on March 28, 2021 Permalink | Reply
    Tags: "Who’s who on the ELT - Part III", , , , , ESOblog (EU),   

    From ESOblog (EU): “Who’s who on the ELT – Part III” 

    ESO 50 Large

    From ESOblog (EU)

    26 March 2021
    People@ESO

    Bigger than all existing optical research telescopes combined, ESO’s Extremely Large Telescope (ELT) will drive astronomy into the future, tackling the biggest scientific challenges of our time. But to construct such an innovative and powerful telescope, it takes many different people working in an enormous variety of roles. In this series of blog posts, we hear from some of the people working on the ELT, exploring the work they do to help us reach the stars.

    Emanuela Ciattaglia (ELT Assembly, Integration and Verification Manager)

    “Since the end of 2016, I have been leading a great, expert team in planning the Assembly, Integration and Verification phase of the ELT on site. This is when all telescope subsystems are assembled together for the first time, and the telescope is finally “switched on” and tuned to get ready to bring distant objects closer to us.

    Since I was a child, I’ve been fascinated with how everything works and kept following my dad repairing cars and things around the house. Studying mechanical engineering meant my fascination finally found some solid explanations in understanding how things can be put together to achieve a function.

    Before the ELT, I worked on ALMA. My first visit to the ALMA site, high up on the Chajnantor plateau, felt like being on another planet, and yet the antennas we had worked on for so long were right there, moving together beautifully.

    Now, I really enjoy that my work on the ELT gives me a wide overview of the first part of the telescope’s life on site: from the arrival of various components, to their assembly and testing, until they are all serving their special functions together in this fantastic machine. Currently, my work days are full of meetings with the team, and the many teams we interface with, to plan the work on site. It is pretty dynamic, with numerous exchanges on many different topics, challenging at times but extremely interesting!

    A very memorable moment was back in 2016: being on the flattened top of Cerro Armazones for the first time was thrilling! I walked across it, thinking about how the work of ESO, all the contractors across many countries and everyone supporting us would one day materialise into a gigantic telescope on that exact soil. In the future, we will be back on that mountain top with so much more experience (and grey hair!), and able to admire the result of all our amazing work.

    Outside work, my family lovingly fills my time. We love trying out different sports together and repairing our cars and bikes. When I have the time, I like playing piano, painting and learning about neuroscience discoveries.”

    Lorenzo Pettazzi (Control Engineer)

    “When you are an engineer any moment you spend in the field is a memorable one, because it very often represents a big step in your personal “learning curve”. ESO’s Paranal Observatory is a very special place where engineers and astronomers are learning every day how to push the limits of technology to refine the art of astronomical observation and expand our knowledge of the Universe. We can use our knowledge and experience from building and operating the VLT at Paranal Observatory in constructing the ELT at Cerro Armazones.

    My fascination with space exploration drew me to study aerospace engineering at the age of 18. Now as a control engineer for the ELT, I am involved in designing and building the devices necessary to move the giant optical elements of the telescope. In particular I am the Workpackage Manager for the M1 Position Actuators, which will control the fine motions of each of the 798 segments of the ELT’s main mirror. The complexity of the projects means my work days are always different! Sometimes I spend the day in the lab testing future ELT actuators, other times I work at my computer simulating the performance of the telescope’s algorithms. I also coordinate the work of colleagues or external contractors to complete these projects. I enjoy working side by side with very talented professionals on the development of cutting edge technologies. The idea of building a unique facility which will shape future astronomical research always keeps me motivated.

    When I am not working at ESO, I enjoy sports including tennis, football, snowboarding and jogging. I sometimes relax by practising my juggling skills, reading comics or taking part in outdoor activities with my family. Last but not least, I am an enthusiastic supporter of AS Roma, the football team of my hometown!”

    Juan Carlos Palacio (Mechanical Construction Engineer)

    “Growing up, there wasn’t much to do in the village I lived in in southern Chile — no internet or video games and it rained all winter, so I spent my time trying to understand physical processes and playing with numbers to solve equations. After high school, I started to study engineering, which narrowed down to mechanical engineering after I was delighted by all of the thermal processes and fluid mechanics in a course of thermodynamics.

    I am now a mechanical construction engineer, which involves participating in technical reviews for the ELT’s dome and main structure and other subsystems. A typical day is spent reviewing mechanical designs and calculations in documentation delivered by contractors, as well as revising the maintainability and reliability of equipment; this is very important to ensure that the time the ELT spends on-sky collecting data for astronomical research is maximised. After working on the VLT at Paranal Observatory for 15 years, I am trying to transfer the experience I gained by contributing information about the typical issues we have faced with the VLT.

    For me, the most remarkable part of the ELT project so far was seeing the first design of the dome rotation mechanism. We have developed this to be able to hold and rotate the telescope’s dome, which will have a mass of more than 6100 tonnes! Participating in meetings with contractors and evaluating their designs is an enjoyable learning process because they bring new ideas that they have implemented in projects in totally different sectors, which opens our minds to investigate whether such technology could be useful for the ELT.”

    Alain Delorme (Contracts and Procurement Officer)

    “My educational background is in economics, and I started working in a sales department. Then one day I had an opportunity to switch to the other side, the purchasing part, first in a commercial business then for the French Ministry of Defence, where I processed the procurement part of high-technology equipment. And I just loved it! When I applied to ESO, the organisation was looking for an engineer with some procurement experience. Instead, I offered strong procurement experience in technological areas.

    Even though I’m not an engineer, I enjoy the technological side of my work. I like to understand what I’m working on, not only my part — the procurement process and commercial and contractual aspects — but also the technical issues, constraints and implications, hence I appreciate the discussions with my colleagues in charge of the technical aspects of the project I am involved in. I also very much like having to deal with a variety of issues and areas. The ELT offers all of that.

    I was specifically recruited in 2010 for the ELT. Although my tasks extend beyond that project, I am heavily involved in ELT procurements since it represents a significant part of our activities. Currently, I am in charge of many of the commercial aspects of the ELT’s different mirrors, including their polishing, coating and washing — the mirrors are very complex so this is a surprisingly large amount of work! My job consists mainly of processing recurring tasks and procurements of systems which usually conclude after a long tendering process. In all cases, I am happy when I consider the outcome of a process satisfactory for ESO. There is a mixture of small and bigger satisfactions. Of course when you witness important milestones of a contract (for example the first blasting of Cerro Armazones), or conclude a negotiation after a process which is complex (the polishing of the primary mirror) or difficult (the edge sensors), these are memorable moments!”

    Elise Vernet (Adaptive Optics Expert)

    “As a teenager, I was an amateur astronomer and built a small Dobsonian telescope, which led me to studying physics at university. In my last year, I specialised in high angular resolution astronomy, which introduced me to adaptive optics systems, an essential technology to achieve sharper images. It was in 1997 and ESO’s 3.6-metre telescope at La Silla Observatory was just providing its first results using this technology. I found it amazing that we could overcome the effects of the atmosphere, using very fast mirrors and sensors to get higher resolution images as if we were observing from space rather than from the ground.

    Now, I continue to work with adaptive optics systems on the ELT. I am responsible for two of the ELT’s five mirrors: the adaptive M4 mirror and the ultralight weight M5 mirror. These two critical subunits are designed and manufactured by external companies, so on a typical day I follow up on the projects, read documents and attend meetings with the companies to try help solve technical issues and find out any risks which could delay the project or increase its cost. As some components of both subunits are already being manufactured and assembled, I am also verifying they meet requirements.

    I really enjoy following up on state-of-the-art projects like the ELT. I do my best to get the very technologically challenging components delivered to specification and on time. I like that every day I’m improving my technical knowledge on aspects of manufacturing and integration, and I enjoy helping test and inspect each subsystem. The most memorable moment in my career so far was back when I was working on the VLT. Installing the deformable secondary mirror on the VLT’s Unit Telescope 4 to provide images corrected for atmospheric effects, gave a second life to the telescope.

    Outside of work, I like making clothes for my whole family. I also have a lot of fun cooking international recipes and visiting foreign countries.”

    Mark Wallace (Expert Control System Engineer)

    “My role involves developing the Interlock and Safety System, which covers the safety interactions of all ELT subsystems to keep both people and the equipment safe. For example, ensuring that the lasers cannot be switched on if people are inside the dome to avoid exposing them to potentially harmful radiation or ensuring that the altitude structure (telescope tube) cannot move while M1 segments are being exchanged to protect the people and mirror segments involved. A typical day involves writing or reviewing design reports and technical memos, testing various hardware configurations and the odd meeting.

    What I enjoy most about my work is being challenged by unusual problems and learning new things. The juxtaposition of the sheer size of the ELT, the requirements on accuracy and precision, and the harsh range of environmental conditions on Cerro Armazones creates myriad challenges. Talking to and working with others at ESO provides plenty of opportunities to learn from their experience.

    I have always enjoyed solving puzzles and in high school, I saw that a career in engineering meant solving real-world problems. I was set on aeronautical engineering, even applying to the Australian Defence Force Academy. In the end, I opted for mechatronics engineering to defer choosing my specialty. Taking mechatronics gave me the opportunity to work on a variety of machines, including making Joint Strike Fighter components. The experience I gained in motion control and functional safety in industry led to my involvement in the ELT.

    A highlight in my career was prototyping large-scale 3D printing combined with 5-axis machining to print large structures quickly and accurately. The tough requirements made every step towards success more rewarding. For the ELT, seeing the site first-hand gave me a better feeling of the project’s enormity than drawings or 3D models ever could.

    Outside work, we recently got a puppy. Meeting other dogs (and their owners) in the park allows me to practice German. I also like skiing and sledding with my kids. My colleagues may not know, but I used to row competitively and if I could find time here in Munich, I would love to get back into it.”

    Fabio Biancat Marchet (Programme Engineer)

    “From the mist of my early memories, I can distinguish the blurred image of that first “small step for man” on an alien world, which probably inspired my future. As a child, I was attracted by the complexity of systems, by the interactions between them and by their intrinsic mechanisms and the possibility of creating new ones.

    I started working for the ELT in 2017 as the Programme Engineer. My duty is mainly to coordinate the efforts of a number of experts and I spend my days communicating with colleagues and contractors or reviewing documentation. What makes this job challenging is the fact that often decisions have to be made relying on partial information and compromises have to be found among conflicting constraints.

    Besides the obvious pride of contributing to one of the biggest scientific enterprises ever, what gratifies me most is the productive interaction with people and feeling part of a team that shares a common objective; where everyone contributes with their own unique skills, background, character and culture. I’m convinced that, whether you’re building advanced astronomical facilities, cars, or washing machines, this is what really enriches you.

    For me, engineering should involve working towards a higher respect for the environment. Visiting the ELT construction site for the first time was a breathtaking experience, and not just because of the over 3000-metre elevation; only there looking at the huge hole in the mountain can one grasp the true breadth of the project. And the depth of that scar reminds us of our responsibility to develop not yet another monument to the arrogance of mankind, but rather a sign of its thirst for knowledge.

    To take my mind off work and relieve the stress, I like to cook, which I find simultaneously challenging and relaxing. And after all, cooking has a lot in common with being an ELT engineer; it requires ingenuity, planning, staying within a budget and schedule, and — most importantly — satisfying customers.”

    Amelie Gnatz (Document Controller)

    “As the ELT Document Controller, I am responsible for keeping the ELT document repository updated and the ELT documents accessible to the authorised users. My goal is to support the ELT staff with documentation matters and ensure the accuracy, quality and integrity of the ELT documents. In cooperation with the project managers and the managers responsible for the different components of the ELT, I take care of the documents delivered by external parties for reviews and prepare documentation packages for procurements. As part of the Systems Engineering Team I am involved in configuration management processes ensuring that the system will perform as intended, and is identified and documented in sufficient detail.

    While documentation is a topic that tends to be overlooked, it plays a key role in each and every project and at each stage of the project. Having in place a well-maintained repository ensures a common source of truth to work with and enables the project to evolve smoothly. Long story short, the ELT repository has the aim to make our lives at the ELT easier.

    The ELT is an unique and complex project that is evolving fast. The repository structure and how we manage the processes of documentation and configuration management need to be constantly adjusted according to the project’s evolution. This makes my role very varied and interesting. Aside from my day-to-day work in Garching, I will never forget my trips to Chile, where I had the chance to see Cerro Armazones — the new ELT site — after the mountain plateau was created. But I think the most memorable moment is yet to come: seeing the complete ELT for the first time.”

    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 (EU) in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    European Southern Observatory(EU) 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”.

    European Southern Observatory(EU) , Very Large Telescope 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.

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light at an elevation of 2,635 metres (8,645 ft) above sea level.

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. A large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile at ESO Cerro Paranal site. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev.

     
  • richardmitnick 10:15 pm on January 29, 2021 Permalink | Reply
    Tags: "Up close and personal with the Miniscule Extremely Large Telescope" MELT, , , , , ESOblog (EU)   

    From ESOblog (EU): “Up close and personal with the Miniscule Extremely Large Telescope” MELT 

    ESO 50 Large

    From ESOblog (EU)

    29 January 2021
    HighTech ESO

    1
    The optical setup which comprises the MELT. Highlighted are the analogues for the M1 and M4 mirrors.
    Credit: ESO.

    2
    Justin Tabbett

    In a laboratory at ESO headquarters, there is a setup of optics, lenses and mirrors aiding the development of the Extremely Large Telescope — the Miniscule ELT, otherwise known as the MELT. Set to test and validate key elements of the ELT, ESO’s upcoming flagship telescope, the MELT serves as a proving ground to learn valuable lessons for commissioning — setting up and operating — the ELT.

    “The MELT has been built to fail and to learn from those failures ahead of the completion of the ELT,” says Carlos Diaz Cano, MELT software engineer and project manager.

    The ELT [below] will be the world’s largest optical and near-infrared telescope with a 39-metre main mirror, the largest of a five mirror setup, and is set to push the boundaries of astrophysical research. For such an ambitious project, it is useful to be able to test specific elements of the telescope and how they interact before it is operational. Scaling down the entirety of the ELT to fit in a lab bench barely six square-metres in area would be a near-impossible task. Instead the MELT emulates only specific components of the ELT with the light passed via four different mirrors connected in a “telescope optical path”.


    Light reflects in five different mirrors in its journey through the ELT.
    Credit: ESO/L. Calçada/ACe Consortium.

    MELT’s main mirror and control software

    One of the highlight features of the ELT is its main mirror, M1, composed of 798 hexagonal segments, with each segment measuring 1.4 metres across and just 5 cm thick. The M1 analogue on the MELT is composed instead of 61 segments, in total measuring just 153 mm across. This analogue mirror was incorporated from a previous ESO experiment, the Active Phasing Experiment, which was done at ESO’s Paranal Observatory and tested the control of segmented primary mirrors for the ELT. After this experiment returned from Paranal, the engineers at ESO headquarters incorporated adaptive optics and additional optical components. With a few additional changes in hardware and almost completely new software and electronic infrastructure, this system is now known as MELT.

    2
    A number of control modules for the MELT controlling several telescope features including motors, light sources, and M5 switches. Credit: ESO.

    Sixty one segments are understandably easier to work with than 798, and give us an idea of the challenges we’ll face with the ELT,” says Pascaline Darré, optical engineer for the MELT. “But we have to bear in mind that the ELT will be different because it’s on another scale.”

    While there are fewer segments on the MELT’s M1 analogue, there is still a substantial amount of work involved in operating them. Each segment needs to move independently to ensure perfect co-alignment of all the segments, enabling them to behave as a single larger mirror — for both the ELT and the MELT. The movement of these segments is managed by control software. An overarching challenge the MELT team are facing is the development and integration of control systems for the miniaturised telescope.

    “The control system is the ‘glue’ that joins all the components together,” says Diaz Cano. “Every bug we fix now is time saved for the ELT in the future.”

    The team has been integrating several control system software products developed to perform different functions on the ELT, to allow the different components on the emulated telescope to communicate with each other. In particular, they have been modernising the control system software to match standards for the ELT.

    “Aside from using the software for MELT, we plan to develop a set of software libraries which will actually be available for use on the ELT,” explains Diaz Cano.

    The MELT’s other mirrors

    On the ELT, M2 reflects the light from M1 to M3 allowing the light to continue on its path between mirrors before being captured by scientific instruments. Although MELT simulates the ELT, its optical design is not identical, and it does not have a M3 mirror. Instead, MELT’s M2 analogue is a special lens assembly that emulates the ELT’s M2 and can also intentionally generate optical aberrations (such as astigmatism). These aberrations blur and distort images, allowing engineers to learn how to correct them on the ELT.

    4
    The Miniscule ELT (MELT)’s M2 analogue is a special lens assembly that emulates both M2 and M3 of the ELT and can also intentionally generate optical aberrations (such as astigmatism). These aberrations blur and distort images, allowing engineers to learn how to correct them on the ELT. Credit: ESO.

    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 (EU) in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO (EU) 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.

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

    ESO VLT 4 lasers on Yepun.

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light at an elevation of 2,635 metres (8,645 ft) above sea level.

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

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

    ESO ELT 39 meter telescope 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/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev .

     
  • richardmitnick 9:13 am on January 16, 2021 Permalink | Reply
    Tags: "Five minutes with Adrian Russell", Adrian Russell looks back on how he got into astronomy and his path to becoming Director of Programmes at ESO., , , , , ESOblog (EU)   

    From ESOblog (EU): “Five minutes with Adrian Russell” 

    ESO 50 Large

    From ESOblog (EU)

    15 January 2021
    People@ESO

    1
    Adrian Russell

    Adrian Russell looks back on how he got into astronomy and his path to becoming Director of Programmes at ESO. He shares with us what some of the most exciting new projects at ESO are, how the field of astronomy has changed in his career and what he is most looking forward to in the future.

    Q. How did you get into astronomy?

    A. When as a kid, I was just the right age when the Apollo moon landings were happening, so I got hooked on science very early on.

    But actually, at university I studied electrical and electronic engineering, not physics. At the end of my first year, I was working a summer job in a factory in Sheffield in the UK. I bought this book from the second-hand bookshop next door called The New Astronomy by John Gribbin. It was the story of the post-war technology revolution that led to radio astronomy and then the discovery of quasars and all kinds of strange objects. I was completely hooked, and I immediately bought a whole bunch more books about astronomy. I was all set to change my degree.

    However, in the Department of Electrical Engineering, there was a poster from the University of Edinburgh, where they did an MSc in Astronomical Technology. So I wrote to Malcolm Longair, who was the Astronomer Royal for Scotland, director of the Royal Observatory in Edinburgh and professor at the university to ask his advice and amazingly he actually wrote back. He said, “Do not stop with what you’re doing at the moment. My first degree was in electrical engineering as well. Send me your course options and try to choose the more physics-related options.”

    From there, my final year undergraduate project was in astronomy-related technology, understanding the impact of the design of the radome on the James Clerk Maxwell Telescope (JCMT) – this is the white wind screen that covers the entrance of the telescope.

    East Asia Observatory James Clerk Maxwell telescope, Mauna Kea, Hawaii, USA,4,207 m (13,802 ft) above sea level.

    At the time it was going to be supported by a series of wires – which would have impacted its performance. After this I did a heavily instrumentation-based PhD in astronomy at the Mullard Radio Astronomy Observatory, before getting a job at the JCMT.

    Mullard Radio Astronomy Observatory (MRAO) One-Mile Telescope at the operated by Cambridge University.

    Q. What led you to your position as Director of Programmes at ESO?

    A. Basically, I gathered more and more relevant experience. I transitioned from helping run instruments on the telescope to managing the JCMT instrumentation when I went back to Edinburgh. I had no idea what management was but with mentoring from the chief engineer at the Royal Observatory, I learned how to interact with groups, build instruments and herd cats!

    The next big step was becoming the UK project manager for Gemini, where I learned about building telescopes and the issues associated with having contracts to do so, then I ended up running the UK Astronomy Technology Centre, with about 100 people.

    When I saw that there was an opportunity to work on ALMA, it seemed like a combination of everything that I had done.

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

    I understood the technology of the single dish instrumentation pretty well and what it was like to build telescopes. It was a big step because I’d never managed a project of that magnitude and it was a complex and international project.

    When the position of Director of Programmes at ESO arose, it just seemed like a fantastic opportunity. ALMA was almost finished and it was the chance to become involved in the Extremely Large Telescope (ELT) early on and be part of the world’s leading optical observatory with a really vibrant instrumentation programme. And it was still working in an organisation that was helping finish ALMA. So it just seemed like an opportunity too good to miss.

    Q. How does the Directorate of Programmes contribute to ESO’s mission?

    A. A big part of ESO’s mission is to develop new technologies, deliver new instruments and telescopes and that’s where we come in.

    Our day job really is entirely looking after these new things that are beyond state of the art: whether it’s the ELT or an upgrade to an instrument like CRIRES.

    ESO ELT 39 meter telescope 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).

    CRyogenic high-resolution InfraRed Echelle Spectrograph. The original CRIRES was removed from UT1 in July 2014 for an upgrade and not offered from P94 onwards. CRIRES was installed on the UT3 Nasmyth B focus in Period 104. Comissioning of the instrument is still pending. Depending on the results of the commissioning, CRIRES will be offered for Period 107. Before then there will be a science verification.

    Our work is to deliver those projects in a timely way and to try and control our appetite for doing too many things at once.

    There are always difficulties with scheduling, with technical issues and in that we’re managing activities that are heavily distributed across big consortia. The scientists and engineers in these consortia are highly competent, but at the end of the day they still need significant support from ESO as well, and that’s a big part of what we do.

    Q. What does a typical day as Director of Programmes look like?

    A. I’m not sure there is a typical day. We run these programmes by empowering the individual programme managers to do their jobs in managing the ELT, and the Paranal Instrumentation and technology development programs. My job involves interacting with them about what the latest issues are. It’s always dominated by a mixture of funding and effort availability. Technical problems come and I hear about them but mostly they get solved by the technical teams because they are extremely competent.

    These days, an awful lot of time and energy is spent by everybody on the ELT and that includes me. The ELT programme manager, Roberto Tamai, is in charge, but I discuss with him a lot about what’s going on with the ELT.

    There are also wider initiatives to try and improve ESO as a whole, which the directors’ team are fairly heavily involved in.

    Q. What do you find particularly rewarding about your role?

    A. Just being able to earn a living doing something I really enjoy is fantastic but if you get more specific than that, the single biggest buzz personally is definitely seeing the progress made by our teams. These days, it’s very rare that I get my hands dirty directly but being able to see the work of so many people empowered to make everything go forward is incredibly exciting.

    On those occasions when I’m at the Paranal Observatory at night, looking up and standing amongst these machines, I still get that tingle down my spine realising that I play a part in what’s generating this. I also really like seeing the results that come out, like the first image of a black hole from the Event Horizon team.

    Messier 87*, The first image of the event horizon of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration released on 10 April 2019.

    EHT map.

    Realising that you’d worked more than half a decade to enable it to happen in some small way is fantastic.

    Q. How would you say astronomy has changed since you started in it?

    A. When I first started some instruments were small enough that you could carry them under your arm. The instruments we are building on the ELT, they are the size of small houses: you could live inside them! The level of complexity, the sheer size, the cost has gone up by orders of magnitude and that has changed things, for the better and for the worse. When I was a PhD student, it was still possible for a student to be heavily involved in building an instrument, take it to the telescope and do science with it. That’s becoming more and more difficult as very large consortia are now building the instruments. You worry about where the next generation of instrumentalists will come from, but obviously they are still involved in projects in different ways.

    So, the scale size of science and how that impacts the ability of individuals on the technology side is a big change. Another is, it’s getting more and more difficult for astronomers to get involved in the technology as opposed to really good engineers getting involved in astronomy, and I think that leadership role is at threat because projects have to be science driven. At ESO, I think we manage a good balance between really good scientists and really good engineers working together but these instrumentally savvy astronomers are still fundamental I think, to being able to design, build, envision and even operate telescopes.

    Q. You’ve been at ESO for 10 years, what are you looking forward to in ground-based astronomy in the next 10 years?

    A. For me, by far the number one thing is for the ELT to see first light, and to come into operation. I’m excited about the new instruments that are getting built and about prospects for technology development, growing and working more with the community and industry, but if I had to pick just one thing unequivocally it’s the ELT.

    On a global scale, I would say it’s the ELTs plural. I’m also sure that the Vera C. Rubin Observatory coming into operation will be breathtaking.

    NOIRLab Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes, altitude 2,715 m (8,907 ft).

    I think that the other big international projects like the Square Kilometre Array (SKA) and the Čerenkov Telescope Array (CTA), the latter of which we are heavily involved in, will be an exciting new thing for ESO as well.


    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.


    SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO).

    Proposed CTA Telescopes, Čerenkov Telescope Array depiction at ESO’s Cerro Paranal Observatory. This image illustrates all three classes of the 99 telescopes planned for the southern hemisphere at ESO’s Paranal Observatory, as viewed from the centre of the array. This rendering is not an accurate representation of the final array layout, but it illustrates the enormous scale of the CTA telescopes and the array itself.

    Q. So it will be interesting to see what happens after the ELT if the scale continues to grow to even bigger telescopes.

    A. Yes, though there is some push back. There are wide-field projects that people are trying to get off the ground, like the Maunakea Spectroscopic Explorer, which are dropping back down again in scale size.

    Maunakea Spectroscopic Explorer Maunakea Hawaii USA altitude 4,207 m (13,802 ft).

    I think everybody has found that ELT-sized telescopes are very hard to get funded.

    Building the VLT over 20 years ago was a huge stretch for ESO as well, so in the intervening period, a global collaboration to afford ALMA was maybe inevitable. I can see that might be a natural model, in that ESO’s next big project might actually be a slightly smaller and globally collaborative project. Our thoughts today are preliminary at best because what we want to do in five years is almost certainly not what we think we want to do now, as it is very much driven by new scientific discoveries and how the ELT will turn out. Which again is what makes it exciting!

    Q. Can you tell me about an interesting new instrument or upgrades at Paranal or La Silla in the next few years?

    A. I think I’m probably most excited by GRAVITY+: upgrading the existing GRAVITY instrument so it can become sensitive enough to really extend optical interferometry into the extragalactic world.

    ESO GRAVITY in the VLTI

    We are also planning a new spectrographic instrument inspired by MUSE but observing in blue light.

    ESO MUSE on the VLT on Yepun (UT4).

    That will also be fabulous and will complement the redder wavelengths observed by the ELT and others. Additionally, ideas about how we might improve the SPHERE instrument are incredibly exciting, as these are all steps towards actually characterising and looking for life on exo-Earths with the ELT in the not too distant future.

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

    Q. Can you tell us about a technology in development that you’re particularly excited about?

    A. One of the most exciting developments already underway when I arrived at ESO was these “avalanche detectors” in the infrared. These are ultra-low noise sensors inside the GRAVITY instrument. We are trying to make these sensors bigger: if they became big enough to be science detectors that would be a truly disruptive technology. Current infrared technology is really being pushed to its limit, so noiseless detectors would be one incredibly exciting area.

    Another area that is unbelievably exciting is what’s happening with solid-state lasers. These are used as artificial guide stars at the telescope to account for most of the distorting effect of the atmosphere, but right now you still need to use real stars in the sky as well. We are researching and developing a different way to measure this distortion using just the lasers, which could give you 100% sky coverage. We’re not guaranteeing that at the moment but that would be such a disruptive technology that it would really impact every observation that uses adaptive optics.

    There are many more things in technology development that are getting on with the job: like developing bigger and faster deformable mirrors so the ELT can find Earth analogues. We need to detect just one photon coming from the planet for every 1 000 000 000 from the star and today nobody knows exactly how to do that, but we need better deformable mirrors and so that work is ongoing. The series of incremental improvements over a number of years could in the end be transformative.

    Q. Finally, what would you do if you weren’t working in astronomy?

    A. I really don’t know; I was going down the electronic engineering path before I got the astronomy bug in a big way and that would have probably moved me into the telecoms area. But I’m afraid I got hooked on astronomy so early on that that dominated.

    These days, I could easily spend a lot of my life doing photography, but I doubt if I would ever make a living that way and maybe it would spoil the fun of the hobby. But at one point astronomy was my hobby, and I certainly have no regrets about choosing it.

    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 (EU) in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO (EU) 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.

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

    ESO VLT 4 lasers on Yepun.

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light at an elevation of 2,635 metres (8,645 ft) above sea level.

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

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

    ESO ELT 39 meter telescope 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/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev .

     
  • richardmitnick 2:27 pm on January 1, 2021 Permalink | Reply
    Tags: "The most popular stories from ESO in 2020", , , , , ESOblog (EU)   

    From ESOblog (EU): “The most popular stories from ESO in 2020” 

    ESO 50 Large

    From ESOblog (EU)

    1
    1 January 2021
    Outreach@ESO

    From watching a star dance around a supermassive black hole to imaging multiple planets around a Sun-like star, 2020 has seen some amazing astronomical discoveries. In this blog post, we look back over some of the most popular images and stories from ESO in 2020.

    The launch of virtual tours

    2
    Screenshot of Virtual guided tour of La Silla Observatory. Credit: ESO.

    During this year, public tours of the ESO observatories in Chile were halted due to the ongoing pandemic. In response, ESO got creative and launched new virtual tours of the observatories led by our specialised guides. These regular tours stream live on ESO’s Facebook and YouTube in both English and Spanish, allowing anyone to explore iconic locations at ESO’s observatories and ask questions to our guides. You can find the schedule of upcoming tours on our Facebook and Twitter using the #TourESO hashtag.

    Most viewed Picture of the Week

    3

    Every Monday, ESO selects one image as its Picture of the Week, including photos of ESO’s sites, telescopes and images created using ESO data. In 2020, the most visited Picture of the Week on ESO’s website was “Death by Laser?“.

    What appears to be a terrible cosmic weapon in this image is in fact the four orange laser beams from ESO’s Very Large Telescope (VLT) shooting into the atmosphere. These laser beams are part of the VLT’s cutting edge Adaptive Optics Facility, helping measure the blurring effects of the Earth’s atmosphere. The laser beams are directed towards the Carina Nebula, among the largest in the southern sky, which appears as a vast pink cloud of gas and dust in this image.

    You can share your images of ESO sites and data from our telescopes on our Flickr page.

    Most read ESOblog post

    4
    This artist’s rendering shows the Extremely Large Telescope in operation on Cerro Armazones in northern Chile. The telescope is shown using lasers to create artificial stars high in the atmosphere [also shown below]. The first stone ceremony for the telescope was attended by the President of Chile, Michelle Bachelet Jeria, on 26 May 2017. Credit: ESO/L. Calçada.

    The most read ESOblog post of 2020 investigated what ESO’s Extremely Large Telescope (ELT) will reveal about the Universe. This post featured an interview with ELT Programme Scientist Michele Cirasuolo where he discusses how the ELT is a giant technological leap forward, that is only possible due to lessons learnt building ESO’s VLT and technology developed using it, and what new discoveries the ELT may make.

    The sheer size of ESO’s ELT (its main mirror is 39 metres across, compared to 8.2 metres for each unit telescope of the VLT) offers exciting scientific possibilities. The ELT can act as a window into what the Universe was like in the cosmic dark ages, 13 billion years ago, by starting to resolve objects in the very distant Universe. The enormous light collecting power of the ELT will also allow astronomers to really start characterising exoplanet atmospheres to see whether they may be suitable for life and perhaps find new Earths. However, what Michele finds most exciting about the ELT is the potential for discoveries that are completely unexpected that allow us to ask new questions that previously we hadn’t thought of.

    Most liked image on Instagram

    5

    On 2 July 2019, ESO’s La Silla Observatory was host to a rare astronomical event, a total solar eclipse. Inaugurated in 1969, La Silla Observatory led ESO to the front line of astronomical science. The 50th anniversary last year celebrated La Silla’s continued contribution to science, and coincided fortuitously with the shadow of the total solar eclipse, or umbra, passing over the site.

    Captured in this image is the stunning view of the total solar eclipse, a rare event which lasted for less than two minutes that day. During a total solar eclipse, the Sun and Moon cross paths in the sky, overlapping perfectly, a feat only possible because the Sun and Moon happen to be the right distance from the Earth to take up the same portion of the sky.
    A few stars shine bright for a moment while the Sun’s brilliant corona halos the Moon, like shimmering strands of silk. A truly breathtaking experience, one that will not occur again at La Silla until the year 2231. Credit: ESO/ M. Zamani

    Most viewed announcement

    6

    Aside from the rolling announcement on COVID-19 safety measures taken by ESO, the most viewed announcement this year was the Milestones Reached in Incredible Journey of ELT Main Mirror Segments. At 39 metres across, the main mirror of ESO’s ELT is too large to be crafted from a single piece of glass. The main mirror will instead be composed of 798 hexagonal segments each 1.4 metres across and 5 cm thick, which must be precisely engineered to work as one giant mirror and deliver unprecedented astronomical data. A number of new milestones important for creating the centrepiece of the ELT were discussed, including the inauguration of the ELT polishing facility in Poitiers, France. Here, the round mirror segment blanks are ground and polished to level them to an accuracy of tens of nanometres. Segments are then cut into the hexagonal shape and even more precisely polished.

    Most popular photo press release

    7

    Images of systems with multiple planets are very rare. Back in July, ESO announced that for the first time, multiple planets had been directly observed around a star like our Sun. Observations from this study, led by Alexander Bohn from the University of Exeter, and others can help astronomers understand how planets formed and evolved around our own Sun.

    The above image captured by the SPHERE instrument on ESO’s VLT shows the star TYC 8998-760-1 (in the top left corner) accompanied by its two giant exoplanets.

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

    The image was captured by blocking most of the light from the young, Sun-like star using a coronagraph, which allows the fainter planets to be seen but causes artefacts (the bright and dark rings around the star). This system is very different from our own, with the inner and outer planets fourteen and six times heavier than Jupiter respectively. The below video shows that these planets are much more distant from their star than Pluto is from the Sun.


    View of the orbit of two exoplanets around TYC 8998-760-1
    Credit: ESO/L.Calçada/spaceengine.org

    Most watched ESOcast


    ESOcast 231 Light: Death by Spaghettification.
    Credit: ESO.

    The most watched ESOcast video this year accompanied the press release on Death by Spaghettification, explaining how a star is ripped apart and devoured by a black hole. Researchers led by Matt Nicholl from the University of Birmingham, UK, pointed ESO’s VLT [below] and ESO’s New Technology Telescope [below] at the rare blast of light caused by this violent event, 215 million light-years from Earth, finding it can launch a powerful blast of material outwards. The full artist’s animation of the star being devoured can be watched here. This and other videos from ESO can be viewed on our YouTube channel.

    Most popular organisational release

    8

    A new study commissioned by ESO to evaluate the impact of 18 satellite constellations on astronomical observations was released in March, becoming ESO’s most popular organisational release of 2020. Astronomers were concerned by what impact the satellite mega-constellations under development by SpaceX, OneWeb and others would have on scientific research.

    The study found that ESO’s VLT and future ELT would be ‘moderately affected’ by these 26 000 satellites, especially for long exposures between sunset and dusk. However, wide field surveys, especially by larger telescopes like the US National Science Foundation’s Vera C. Rubin Observatory, would see up to 30% to 50% of exposures “severely affected”, depending on the time of night and other factors.

    NOIRLab Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes, altitude 2,715 m (8,907 ft).

    A conversation has since started between astronomers, engineers and satellite companies to try to mitigate the effects of satellite mega-constellations, as reported in this announcement in August. The astronomical community can help by identifying ways to lower satellite brightness and developing software to mask satellite trails or calculate satellite paths to avoid them. Satellite operators could launch fewer satellites, and reduce how much light they reflect by changing satellite altitudes and darkening spacecraft or using sunshades. SpaceX are now deploying a sunshade on all new Starlink satellites to reduce their visibility on the night sky though they will remain detectable by even small observatories.

    Most popular press release

    9

    ESO’s most popular press release of 2020 across the internet announced, in May, the discovery of the closest black hole to Earth so far. Lying just 1000 light-years from Earth, this black hole forms part of a triple system, and is also the first where its two companion stars can be seen by the naked eye. The team, led by ESO scientist Thomas Rivinius, were analysing their observations of what was believed to be the double-star system HR 6819, and were stunned to discover a third object: a black hole. Using the FEROS spectrograph on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory showed that one of the two visible stars orbits an unseen object, at least four times more massive than our Sun, every 40 days.

    ESO FEROS Fiber-fed Extended Range Optical Spectrograph (FEROS) was originally installed on the ESO 1.52-metre telescope in 1998. After this telescope was decommissioned, FEROS was moved to the MPG/ESO 2.2-metre telescope, where it had first light in 2002.

    The video below shows the system, with the second star orbiting the inner pair on a longer period.


    View of the orbit of two exoplanets around TYC 8998-760-1
    Credit: ESO/L.Calçada/spaceengine.org

    The system can be seen by the naked eye from the southern hemisphere within the constellation of Telescopium on a dark, clear night. The team believe this system could be the tip of the iceberg and help provide clues where many hidden black holes in the Milky Way could be.


    Artist’s animation of the triple system with the closest black hole. The orbits of the two stars are seen in blue and the invisible black hole’s orbit is shown in red. Credit: ESO/L. Calçada.

    10
    Simulation image showing the orbits of stars very close to the supermassive black hole at the heart of the Milky Way.
    Credit: ESO/L. Calçada/spaceengine.org

    Finally, a Nobel Prize

    Last in this roundup, the 2020 Nobel Prize in Physics was partly awarded to Reinhard Genzel, who has worked in collaboration with ESO developing instruments for around 30 years, for his work on the supermassive black hole, Sagittarius A*, at the centre of our galaxy. Genzel, Director at the Max Planck Institute for Extraterrestrial Physics in Germany, shares half of the prize with Andrea Ghez, a professor at the University of California, Los Angeles in the US, “for the discovery of a supermassive compact object at the centre of our galaxy”.

    Star S0-2 Andrea Ghez Keck/UCLA Galactic Center Group at SGR A*, the supermassive black hole at the center of the Milky Way.

    Both Genzel, using ESO telescopes [below], and Ghez, with the Keck telescopes in Hawaii, have conducted observations to track the orbits of stars at the centre of the Milky Way and enable insight into Sagittarius A*.

    Keck Observatory, two 10 meter telescopes operated by Caltech and the University of California, Maunakea Hawaii USA, altitude 4,207 m (13,802 ft).

    Specifically, by tracking a star named S2, Genzel’s team found the light it emitted was stretched to longer wavelengths, confirming for the first time Einstein’s predictions of the effects of general relativity near a supermassive black hole.

    Star S2 near SGR A* at the center of the milky Way studied by Richard Genzel of MPE.

    The ELT’s higher angular resolution will allow astronomers to probe the behaviour of stars even closer to the black hole in future, and take testing relativity to another level.

    The video below shows the system, with the second star orbiting the inner pair on a longer period.

    The system can be seen by the naked eye from the southern hemisphere within the constellation of Telescopium on a dark, clear night. The team believe this system could be the tip of the iceberg and help provide clues where many hidden black holes in the Milky Way could be.

    See the full article here .


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    ESO (EU) 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.

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

    ESO VLT 4 lasers on Yepun.

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light at an elevation of 2,635 metres (8,645 ft) above sea level.

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

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

    ESO ELT 39 meter telescope 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/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev .

     
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