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  • richardmitnick 2:04 pm on November 22, 2019 Permalink | Reply
    Tags: "Illustrating the cosmos", , , , , ESOblog, Luis Calçada, Martin Kornmesser   

    From ESOblog: “Illustrating the cosmos” 

    ESO 50 Large

    From ESOblog

    22 November 2019

    1
    Outreach@ESO

    Did you know that the beautiful images of the cosmos that we see online and in books don’t typically come directly from telescopes? Raw, black and white images are processed into colourful photos that not only look stunning, but also bring out fine details to help scientists understand more about the Universe. At ESO, this processing is partly done by our visual artists, Martin Kornmesser and Luis Calçada. But their work doesn’t stop there; Martin and Luis also illustrate mysterious objects that we can’t use telescopes to image clearly or directly — making the invisible visible and helping us imagine the most mysterious parts of the Universe.

    Q. First of all, why don’t we show the images as they are collected by the telescopes and how do you transform raw telescope images into stunning images of the cosmos?

    MK: We initially get many images of the same object, each of which is a record of a different wavelength of light. These images come in FITS format — a digital file format that is commonly used in astronomy. We assign a colour to each wavelength and layer these images on top of each other to make one nice coloured image.

    Below is an image before and after I processed it. Some images are more difficult to process than others; a mosaic image from ESO’s VLT Survey Telescope (VST) [below], for example, involves a lot more work than a Hubble Space Telescope image, because it contains billions of pixels. The challenge with giant images is that they need to look good when you zoom out and also when you zoom in. But in the end, the VST wide-angle images are among my favourites. Totally worth all the effort.

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    The Cat’s Paw Nebula, before (left) and after processing and mixing all filters (right).
    Credit: ESO

    Q. How do you create an artist’s impression to visualise something we can’t yet image directly, like the surface of an exoplanet?

    Luis Calçada (LC): Often, we cannot see them close up, but scientific analysis reveals most of the physical processes behind these objects or events. This means that we can usually (at least partly!) guess how something looks. We know the velocities, we know the scales, we know the temperature, and that all translates into something physical, something visual. For example, if an object has a certain temperature then we know it emits radiation at a certain wavelength, so we can assign colours to it.

    3
    This artist’s impression shows how jets from supermassive black holes could form galaxies, thereby explaining why the mass of black holes is larger in galaxies that contain more stars. Credit: ESO/L. Calçada

    That’s exactly why it’s interesting to create these images, because we can work out how an object looks to some extent. It’s not just down to the imagination, it is also based on science.

    Q. How long does it take you to create an image or an animation?

    LC: We’ve had cases where we have spent a couple of weeks on some stuff when it is very important, like for the images and simulations we created for the release of the first image of a black hole earlier this year. But for weekly press releases sometimes we take just one or two days. Some things are quicker than others; we’ve done so many exoplanets, for example, that for them it’s just a case of changing the colour and composition to match the new observations. It’s different when we’re drawing or animating something completely new.


    Superheated material swirling around the black hole at the heart of Messier 87, which was imaged by the Event Horizon Telescope. Credit: ESO/M. Kornmesser

    Messier 87 supermassive black hole from the EHT

    Q. What does a typical working day at ESO look like for you?

    MK: Luckily there are no typical days at work for me. I’m fortunate to be able to work with talented people on a lot of different projects. We work on visuals for the ESO site, for the ESO Supernova Planetarium & Visitor Centre, and also the Hubble Space Telescope, so it doesn’t get boring very often.

    The best days for me are of course the ones where I am let off the leash, allowed to do whatever I want without restrictions, such as illustrating abstract physical phenomena in frontier science where nobody really knows what it should look like. A dream for every artist.

    Q. How did you come into this role? Is this a career you always knew you wanted?

    LC: When I was studying astronomy, I started working in a planetarium and I thought, “oh, we need some visuals for this”, so I gave it a go. I started teaching myself about computer graphics and astronomy animation, and continued developing my skills in that direction before ending up at ESO. Illustration was not something I’d thought about as a kid but when I got into it, I really enjoyed it. So for me, combining illustration with astronomy at ESO is the best place I could be.

    5
    Artist’s impression of a baby star still surrounded by a protoplanetary disc in which planets are forming. Using ESO’s very successful HARPS spectrograph [below], a team of astronomers has found that Sun-like stars which host planets have destroyed their lithium much more efficiently than planet-free stars. This finding does not only shed light on the low levels of this chemical element in the Sun, solving a long-standing mystery, but also provides astronomers with a very efficient way to pick out the stars most likely to host planets. It is not clear what causes the lithium to be destroyed. The general idea is that the planets or the presence of the protoplanetary disc disturb the interior of the star, bringing the lithium deeper down into the star than usual, into regions where the temperature is so hot that it is destroyed. Credit: ESO/L. Calçada

    7
    This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. Credit: ALMA (ESO/NAOJ/NRAO)

    Martin is a graphics designer which is nice because we really complement each other. He has the formal art background and I have the astronomical one. He has already been working here for something like twenty years though, so by now he’s got a pretty good knowledge of astrophysics!

    Q. Martin, when you started working at ESO, image processing technology must have been quite different. How has the software changed over the years and how does that impact your work?

    MK: Besides the very much improved computer power and reliability, actually not much has changed. Although artificial intelligence is coming into play more and more, for example for sharpening, noise reduction etc., the most important things are still to have a clear vision of where you want to go, and being careful not to overdo it. My motto is “Maximum Natural”, meaning I try to squeeze everything out of the data without going overboard.

    8
    This colour-composite image of the Helix Nebula (NGC 7293) was created from images obtained using the Wide Field Imager (WFI), an astronomical camera attached to the 2.2-metre Max-Planck Society/ESO telescope at the La Silla observatory in Chile [below].

    MPG/ESO 2.2 meter telescope at Cerro La Silla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres

    Wide Field Imager on the 2.2 meter MPG/ESO telescope at Cerro LaSilla

    The blue-green glow in the centre of the Helix comes from oxygen atoms shining under effects of the intense ultraviolet radiation of the 120 000 degree Celsius central star and the hot gas. Further out from the star and beyond the ring of knots, the red colour from hydrogen and nitrogen is more prominent. A careful look at the central part of this object reveals not only the knots, but also many remote galaxies seen right through the thinly spread glowing gas.

    This image was created from images through blue, green and red filters and the total exposure times were 12 minutes, 9 minutes and 7 minutes respectively.

    This image is available as a mounted image in the ESOshop.
    Credit: ESO

    Q. Do you have an idea of the impact your images or animations have online or in the media?

    LC: Since I joined ESO thirteen years ago, I have produced a lot of images that have been used on book covers and even on Wikipedia. It’s interesting when you look up some phenomena and go onto the Wikipedia page and there’s your image! I feel lucky to have produced some images that go down as the recorded image for a certain phenomena.

    MK: For example my illustration of the Solar System ended up as the main image on the Wikipedia page for the Solar System!

    Q. What do you think the future will look like for astronomical images?

    MK: Over the next few years, two exciting new telescopes will arrive on the scene, the James Webb Space Telescope and the Extremely Large Telescope (ELT). Both will primarily observe near-infrared light, with James Webb providing crisp images from space, and the ELT providing images with an incredible amount of detail.

    These new telescopes will confront our imagined illustrations with real images, which is always exciting. In 2009 we illustrated the atmosphere of Pluto, way before the New Horizons spacecraft took photos of the planet close-up. The real images were so similar to our illustrations!

    Also, I think that in the future images will be processed more and more by artificial intelligence, rather than one person using one computer.

    9
    Artist’s impression of how the surface of Pluto might look, according to one of the two models that a team of astronomers has developed to account for the observed properties of Pluto’s atmosphere, as studied with CRIRES. The image shows patches of pure methane on the surface. At the distance of Pluto, the Sun appears about 1,000 times fainter than on Earth. Credit: ESO/L. Calçada

    10
    Real observation of Pluto, taken by NASA’s New Horizon Spacecraft on 14 July 2015. Credit: NASA/JHUAPL/SwRI

    NASA/New Horizons spacecraft

    Q. What advice would you give to someone looking to get into space illustration?

    MK: My advice for everyone interested in image processing would be; get the best out of the newest technology but don’t get carried away. I think we have all seen images which look more like a psychedelic-neon-pizza than a nebula. So don’t do everything possible just because it is possible.

    Q. What do you think is the most exciting part of your job?

    MK: From the feedback we get from the millions of followers and astronomy enthusiasts around the world we know how much people love space images, and how much these images help connect people with the sometimes complicated scientific discoveries that ESO conveys. We seem to touch people on a deep emotional, sometimes even spiritual level with our images; for me, this is probably the most rewarding aspect of our work.

    You basically start with a blank sheet of paper and infinite possibilities. It is really fascinating to understand and fully master the tools that we have nowadays. Whether it’s image processing, animations or video editing, aligning the vision of an artist and the hard facts coming from a passionate scientist is pretty cool.

    11

    The first detected interstellar asteroid `Oumuamua being discussed at The Late Show with Stephen Colbert, with Martin’s illustration of the asteroid in the background. The illustration was based on observations by the Very Large Telescope [below] and the Hubble Space Telescope.

    NASA/ESA Hubble Telescope

    Credit: ESO/M. Kornmesser/The Late Show with Stephen Colbert

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

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

    ESO/HARPS at La Silla

     
  • richardmitnick 4:11 pm on October 18, 2019 Permalink | Reply
    Tags: , , , , , ESOblog   

    From ESOblog: “50 years of CCDs” 

    ESO 50 Large

    From ESOblog

    18 October 2019

    The story of a detector that changed the course of astronomy.

    1
    HighTech ESO

    In 1969, two researchers designed the basic structure of a CCD — or charge-coupled device — and defined its operating principles. These devices have since played a very important role in astronomy, as well as in our daily lives. We talk to Olaf Iwert, Josh Hopgood and Mark Downing, three CCD (detector systems) experts working here at ESO, to find out how CCDs revolutionised astronomy, how they have evolved during the last half century, and what their future might look like.

    2
    A technician holds Hubble’s ACS WFC instrument, which contains a CCD device. Credit: NASA/ESA and the ACS Science Team

    Q. How were CCDs invented and why was there a need for them at the time?

    Olaf Iwert (OI): The CCD was originally developed as a memory device, but people quickly realised that they could also be used for imaging. They are now used in most astronomical imaging instruments, as well as in many digital cameras and early smartphone cameras.

    Interestingly, Kodak’s management initially completely ignored CCDs as they wanted to promote the film segment of their company. The strongest driver was actually most likely the Cold War and the resulting reconnaissance applications; the CCD technology used in the Hubble Space Telescope was not the first of its kind but a “left-over” of the United States’ Cold War reconnaissance programme! Surely the Cold War and the push for Hubble were very strong drivers of scientific CCD technology development.

    CCD-guru Jim Janesick was doing CCD research for Hubble at NASA’s Jet Propulsion Laboratory, but we don’t know whether the military were secretly using even more advanced devices before that time. We do know for sure that companies involved in military business played an important role in CCD development, and in my view, from then on civil astronomy and military CCD applications went hand-in-hand, as the requirements were quite similar. Now, to my knowledge all ESO instruments observing visible light use CCDs, as these detectors continue to be the state-of-the-art in this field.

    The use of CCDs in everyday photography happened about 20 years later than the application of scientific CCDs to astronomy; the astronomical CCDs were the pioneers of digital photography. But there is a big difference between the scientific CCD image sensors that we use at ESO for astronomy and commercial CCDs such as the ones used in video cameras. Scientific CCDs are thinned, backside illuminated, and surface-treated to collect as much information as possible about the observed object. Scientific CCDs are also typically monochrome, meaning that they don’t filter colours so they collect all of the available light with the highest possible efficiency. Commercial CCDs, on the other hand, mostly produce colour images.

    Q. What made the manufacturing of CCDs possible?

    Josh Hopgood (JH): The first CCD was developed by two physicists at Bell Labs, Willard Boyle and George Smith, who were originally interested in transistor technology, which was invented around 20 years before the CCD. As the first CCD was produced using a transistor manufacturing facility, I would argue that the invention of the CCD at least required the invention of the transistor. As is usually the case, the detectors themselves and the manufacturing technologies used are developed in parallel ⁠— scientists and engineers (and the occasional entrepreneur!) are constantly pushing the boundaries of what is possible. Modern CCDs rely heavily on a number of very well-developed manufacturing technologies, and it will probably be the case that novel uses of these technologies give rise to the next generation of detectors for astronomy.

    3
    The “Conveyor Belt” analogy to explain how CCDs work. A more thorough explanation of this can be found here. Credit: From: slideplayer.com/slide/4990634/

    Q. So how exactly does a CCD work?

    OI: A CCD is a two-dimensional array of millions of pixels, each of which collects photons of light and converts them into an electric charge when the CCD is exposed to light. Instead of using a wire to sense the charge from each pixel, the charge is first transferred vertically and then horizontally to reach a single output amplifier that measures the amount of charge from each pixel. The classic analogy is to think of a CCD as a set of rain-collecting buckets along a series of conveyor belts; first the conveyor belts move the buckets in one direction, onto a single conveyor belt that moves all the buckets in a perpendicular direction to pour the water into a measuring cylinder that measures the amount of water in each bucket one-by-one.

    JH: An interesting side note: CCDs convert light into an electrical signal by means of a physical principle called the “photoelectric effect”. It was discovering this effect that led Einstein to figuring out the foundations of quantum physics!

    Q. What advantage do CCDs have over other types of detectors?

    OI: CCDs were the first two-dimensional array semiconductor imaging devices to be invented. Compared to their predecessors, they have a much higher spatial resolution, are better at imaging bright sources of light, are more rugged, and consume less power. And as they started being mass produced for commercial uses, they also became much cheaper.

    Every detector has several sources of noise, but CCDs have less noise than their predecessors. For example, converting electrons into a voltage at the output amplifier always creates some noise, but because CCDs “read out” the electrons produced by each pixel slowly and the geometry of the output transistor is optimised, this source of noise is very low.

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    A CCD on the Very Large Telescope (VLT)’s ESPRESSO instrument. Containing 81 million pixels, this is one of the world’s largest monolithic CCDs. Credit: ESO/Olaf Iwert

    Q. How have CCDs changed over the last fifty years?

    OI: They have improved greatly in so many ways. For a start, they now contain more pixels. The pixels can also be larger or smaller depending on the instrument’s optical design. We now also have optimised output transistors with less “readout noise” whilst operating at a higher speed, more efficient charge transfer, improved mechanical packaging for better cooling, higher quantum efficiency, less dark current noise, fewer defects inside the imaging area, better optical coatings, higher reliability…the list goes on! Another development is that CCDs can now be specially designed to be optimally sensitive to specific wavelengths of light. An example for this is the use of optimised detectors for the blue and red ends of the visible spectrum, as for example used in the Very Large Telescope’s ESPRESSO instrument.

    Q. Josh, you previously worked at one of the major world producers of CCDs. What is it like to now work at an observatory where the same CCDs are used?

    JH: From a personal perspective I find it very rewarding to see the detectors put into use, especially for such grand-scale purposes! I would say that it’s often easy to contain oneself within a bubble, and then forget how your work impacts other people around the world. Taking the position at ESO was a real eye-opener for me!

    Q. Olaf mentioned CCDs being used in digital cameras; what other applications are there?

    JH: CCDs are used for lots of different things! Here’s a quick selection of some of the more interesting applications:

    CCDs perform particularly well whenever you want to take a picture of something bright and something faint at the same time. For this reason, they are employed not only in astronomy, but also in life sciences research. For example, it has been possible to use a CCD to image the fluorescence from a marker molecule inside the brain of a living mouse!
    As well as being sensitive to visible light, CCDs are also sensitive to X-rays, and therefore the dental market is quite significant.
    Line-scan CCDs have extremely fast frame rates, and are used for quality-control checks on production lines for items such as circuit boards.
    When combined with other technologies, CCDs make extremely good night vision cameras, and are therefore employed in search and rescue cameras, as well as military applications.
    Though becoming less favoured, CCDs are indeed still employed in many high-end digital photography/videography systems.

    Q. Do you know approximately how many CCDs are sold worldwide every year?

    JH: For large detectors that are at the core of space-based and ground-based astronomical research, such as the ones used at ESO, I would estimate that a few dozen detectors are delivered worldwide to customers each year; perhaps more than 50, but probably not as many as 100. For other applications, the number could vary from a few hundred to a few thousand per year, but this is steadily decreasing as new technologies offer cheaper solutions with similar performances. We’re already seeing the gradual decline of the CCD market due to other competing technologies, which has led to the closure of some CCD manufacturing lines.

    5
    The OmegaCAM camera lies at the heart of the VST. This view shows its 32 CCD detectors that together create incredibly detailed 268-megapixel images. Each detector measures about 6 cm by 3 cm. Credit: ESO/INAF-VST/OmegaCAM/O.Iwert

    6
    Detail view of the upper left corner of the CCD. The individual pixels are clearly visible. Image taken in 1994. Credit: ESO/H.H.Heyer

    Q. So do you think that another type of detector will become more common in the future?

    JH: CCDs are certainly still relevant for ground-based astronomy, and will be for at least another 5–10 years because their large number of pixels and high dynamic range are practically unrivalled by the current generation of new technologies. However, the ground-based astronomy market is a very small one, and it therefore tends to be a technology-follower rather than a technology-driver.

    What I mean by this is that larger markets such as space-based astronomy tend to dictate developments in sensor technology, and ground-based astronomy will be forced to adopt these new technologies as the older sensor types become obsolete and/or no longer produced. The most likely successor to CCD technology is CMOS Image Sensors, however I would argue that a significant amount of development is required to bring this technology up to the standards that astronomers are used to when making observations with CCD-based systems. In the longer-term future, I am looking forward to the development of an MKID-based imaging sensor for astronomy, as these should be able to tell us not only the intensity of a light source, but also the colour and arrival time of each photon!

    Mark Downing: I agree. Unfortunately, technology moves on and while CCDs are almost perfect detectors, newer cheaper technologies such as CMOS Image Sensors are on the horizon, and these will replace our scientific CCDs in the next few years. This has already happened in commercial cameras and mobile phones. The mobile phone industry is very large and leads to technology innovation in so many areas, but ESO is also at the forefront of innovation with its own CMOS Image Sensor development programmes.

    Q: Mark, you work with a type of CCD specially designed for adaptive optics. Could you explain what this means and why CCDs are the right tool for the job?

    MD: Some ESO telescopes make use of deformable mirrors to reduce the distorting effect of the atmosphere on starlight. We use these high-speed CCDs to detect the “twinkling of the stars”. The images we observe with the CCDs tell us how to move our deformable mirrors to take out the “twinkling” to obtain very sharp images. This is called adaptive optics. Without this improvement in image quality, large telescopes like the Extremely Large Telescope (ELT) would not be feasible.

    High frame rates are required to track the profile of the atmosphere which changes on very short timescales. The technologies we use for these types of CCDs are very special because they allow us to read them out at high frame rates with almost zero noise. This is essential because we choose “guide stars” close to objects we want to observe to correct for atmospheric distortions, and these are often very faint.

    7
    The ELT with two of its cameras, ALICE and LISA. ALICE will use a CCD developed by Teledyne e2v on behalf of ESO. LISA will use a new CMOS Image Sensor which is currently under development also by Teledyne e2v. Credit: ESO

    Q. Do CCDs require special conditions to work? If so, how does ESO ensure these conditions?

    MD: To get the best performance out of our CCDs, we cool them to very low temperatures in the range of -40°C to -120°C to reduce what we call “dark current”. Dark current is created by thermally-excited electrons (rather than light-excited electrons), and is the noise signal you get when there is no light. The lower the temperature the lower the dark current. If you want to see the faintest objects (which are often the most interesting!) then you want to reduce the dark current to almost zero.

    To achieve this, we mount the CCDs inside a sealed metal housing called a cryostat, in which there is no air. The principle is similar to keeping a hot drink warm in a thermos, except instead of keeping something warm, we want to keep our CCDs cold. Inside the cryostat with the CCDs is a cooling source such as a tank of liquid nitrogen, an electrical cooling device, or an electro-mechanical machine called a cryocooler.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

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

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

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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level


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

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

     
  • richardmitnick 12:47 pm on October 4, 2019 Permalink | Reply
    Tags: Astronomer Jos de Boer, , , , , , , ESOblog,   

    From ESOblog: “Witnessing the birth of planets” 

    ESO 50 Large

    From ESOblog

    4 October 2019

    Astronomer Jos de Boer on how he searches for baby planets around young stars.

    1
    Jos de Boer

    The discovery of thousands of exoplanets over the last thirty years has raised many questions: where did they come from? how were Earth and the other planets in the Solar System born? could we increase our chances of finding life elsewhere in the Universe by improving our understanding of how planets are born? We speak to Jos de Boer, an astronomer at Leiden Observatory who uses ESO’s Very Large Telescope to study protoplanetary disks, which are the birthplace of baby planets.

    2
    Science Snapshots

    Q. To start off, why do you think it’s important to find out about how planets are born?

    A. There are two sides to answering this question. On one hand, it’s easy to take the existence of Earth, the Sun and humanity for granted, but “where did we come from?” is one of the oldest philosophical questions. Finding out how planets are formed tells us something about ourselves and our origins. And of course it’s impossible to go back in time, so looking at other planetary systems that are still in formation might tell us some general rules that we could apply to the formation of our own Solar System.

    On the other hand, we want to know where to look for extraterrestrial life. Finding out how planets are born helps us predict how many planets we could expect to find around different star types, where they might be positioned, and whether they might be capable of harbouring life.

    Personally, I think that now we know that planets exist around other stars, it should make us more humble as we realise our situation is not that unique, and that maybe we are not alone in this Universe. It might also change the way we look at and treat our own planet, influenced knowing how fragile Earth is and how easily it could have been born incapable of harbouring life, or indeed could evolve into a state where it can no longer support life.

    3
    Artist’s impression of exoplanet WASP-19b. Credit: ESO/M. Kornmesser

    Q. So how are baby planets born?

    A. It starts off with a molecular cloud, often aptly called a “stellar nursery”, which is a giant cloud of gas and dust. When disturbed by a pressure wave, parts of the cloud can collapse. The densest part at the centre of a collapsed region becomes a young protostar, and the surrounding material either falls onto or starts spinning around the protostar, flattening until it becomes a dusty disk. Over the following 10 000 years, the star gets brighter and its radiation pushes the gas and dust away until the molecular cloud has dissipated. We are left with a bright star surrounded by a gassy and dusty protoplanetary disk, which is the building material for planets.

    The question is what happens within this protoplanetary disk at the moment when the molecular cloud dissipates and we can start seeing it. Are planets already present at this point, or do they form later on?

    The hypothesis that a star system starts off as a cloud of gas and dust was first suggested by philosopher Emmanuel Kant way back in the 18th century. Kant already proposed that this cloud would flatten into a disk, which forms the building blocks for planets. This was then later developed into two competing theories: in the first, part of the disk collapses quickly to form a planet, and in the second, a planet grows gradually in a region where the density is slightly larger than elsewhere — starting small and gathering more and more dust and gas until it is a fully-fledged planet. The reality may depend on where in the disk the baby planet is, but we haven’t been able to fully figure this out yet.

    4
    Artist’s impression of a protoplanetary disk around a young star. Credit: ESO

    Q. It seems like there are still a lot of mysteries surrounding planet formation within protoplanetary disks?

    A. Yes, definitely!

    There are many possible explanations for why things could happen. We have long-hoped to find a simple explanation for an equally simple protoplanetary disk structure, but now that we can image disks in great detail, we see that their structure is far from simple. As a result, our simple explanations do not suffice.

    There are many possible explanations for the structures we see in disks such as cavities, gaps and spiral arms, but no known golden formula for planet formation, for example to explain whether planets form in a specific place or at a specific time in the disk’s evolutionary lifetime. Our Solar System contains rocky planets closer to the Sun and gas giants further out; we thought this might be a general rule, but no, we’ve seen gas giants orbiting close to other stars. At the moment, our theories and observations don’t match and we cannot predict what kind of planetary system will form when we see any particular protoplanetary disk.

    Q. You are using the Very Large Telescope (VLT) to uncover the mysteries behind planetary systems. How and why are you doing this?

    A. I’ve been involved in using two very unique instruments to look at protoplanetary disks — SPHERE and MUSE, both on the VLT — using a technique called high-contrast imaging. The main difficulty with imaging protoplanetary disks is that you have a very bright star surrounded by a very dim disk, so the starlight floods the entire image and it’s very difficult to see anything else. With high-contrast imaging, we block and remove the starlight to better see the surrounding disk.

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

    ESO MUSE on the VLT on Yepun (UT4)

    SPHERE is a dedicated high-contrast imager that is specialised at removing starlight. It contains a so-called “coronagraph” to mask the starlight before it hits the detector. SPHERE has turned out to be fantastic at spotting protoplanetary disks but not so good at finding planets. For planet-hunting, especially for young systems where light from the disk hampers our detection of planets, MUSE may be more suitable. Disks are naturally quite blobby, so it can be difficult sometimes to know whether we are looking at a planet, a blob of dust, or a bit of residual starlight. MUSE takes a spectrum of light for each point in the image which helps us distinguish whether potential planets have the same spectrum as the central star — in which case it is just residual starlight or a disk blob (which reflects the starlight) — or if it looks different, in which case it’s a planet.

    For example, we recently used MUSE to look at a disk SPHERE had already detected (and had found a planet inside!) and MUSE immediately found a second planet. This was fantastic news — the SPHERE detection is the first time a planet still forming in a disk has ever been spotted, and the MUSE detection marks the first time that a system with multiple planets still forming has been found!

    5
    This spectacular image from the SPHERE instrument on ESO’s Very Large Telescope is the first clear image of a planet caught in the very act of formation around the dwarf star PDS 70. The planet stands clearly out, visible as a bright point to the right of the centre of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star. Credit: ESO/A. Müller et al.

    Q. Could you tell us more about how you made this discovery? What makes it so exciting?

    A. People have claimed to detect planets still embedded in disks before, but the claims are far from certain, and I had very strong doubts about all of them. So when we looked at this protoplanetary disk, PDS 70, with SPHERE last year, and saw something that looked like a planet, I was initially very sceptical, however the data did seem convincing.

    But coincidentally, a colleague of mine was testing a new observation mode with MUSE soon afterwards, and needed ideas for stars that would be interesting to try it out with. I suggested PDS 70, just to see what MUSE could do.

    With MUSE, we saw specific wavelengths of light in two places in the image, that match the wavelength emitted by baby planets as they accrete matter. At first we thought it might be a bit of leftover starlight, but then we checked and found that the equivalent wavelength of starlight was slightly different to the light from the two potential planets; this suggests that the accreting material at that point is moving with different velocity to that of the star, which rules out the “leftover starlight” theory. So we had confirmed the presence of two baby planets, and could determine the amount of gas accreting onto them!

    6
    MUSE detection of the two planets around PDS 70 (red and purple boxes). The red and purple graphs show the emission line at a slightly different wavelength than the stellar emission line, indicating that planets are present. The orange graph shows the noise spectrum in the orange boxes surrounding the planet PDS 70c, to show what the spectrum looks like without a planet.
    Credit: ESO/Haffert et al. 2019

    Q. How often do you get to go to Paranal Observatory and what is it like when you are there?

    A. Well I was actually a near-infrared polarimetry specialist for SPHERE, which was installed onto the VLT five years ago. Polarimetric high-contrast imaging takes advantage of light that is scattered by a protoplanetary disk or planet’s atmosphere being polarised in a certain direction; this is the light we see from the telescope and it means that we can separate that light from largely unpolarised starlight. So when SPHERE started making observations in 2014, I went quite often to test the polarimetry high-contrast imaging method. Over time, we’ve got this mode working well and ESO astronomers have got more experience with the instrument, so more and more observations are carried out in “service mode”, where ESO staff astronomers observe on behalf of astronomers around the world. I’ve never been to observe with MUSE though; that’s all been service mode.


    ESOcast 60: A Polarised View of Exoplanets

    Being at Paranal is amazing; I would say it’s one of my favourite places on Earth! The journey there is an adventure in itself — you land in Santiago, and then take another plane to the city of Antofagasta. But then there’s still a bus journey through the mountains to get to the telescopes. The mountains are completely deserted: no trees, no signs of life, nothing! After a couple of hours of driving, the bus finally turns a corner and in the distance you see the plateau at the top of Cerro Paranal, where the VLT stands. If you look in the opposite direction, you see the building site of the Extremely Large Telescope. The bus then stops at the astronomer’s accommodation — the Residencia — which is like a tropical paradise with a very humid atmosphere compared to the dry desert air.

    The telescopes are still just under three kilometres away, and the first night you go up is simply incredible. There are people from around the world making different observations. You see ESO astronomers running the telescopes and visiting astronomers waiting for data to arrive. My favourite thing to do is to exit the building from which the telescopes are controlled, and go out to look at the stars. It takes a minute or so for your eyes to adjust but then the sight of the Milky Way stretching across the sky is just magnificent. If you’re very lucky, you see the lasers shooting up from the VLT, which is very, very cool.

    Q. During your PhD, you spent two years in Chile as an ESO Student. How did that contribute to where you are today?

    A. I stayed mainly in ESO Chile headquarters in Santiago, and went up to the mountain every now and again. Santiago is a hub of activity, with lots of visiting astronomers, lots of talks and lots of interesting discussions. It’s also next door to ALMA Headquarters, which is also full of interesting activity. This all gave me a great insight into what other astronomers are working on.

    Whilst there, I became an expert in polarimetric high-contrast imaging, just because I was in the right place at the right time. This changed the path I was on and led me to a lot of the research I do today. There’s also a small and very international astronomical community in Chile, so it’s a great way to get to know astronomers from around the world.

    Q. What first got you interested in the origins of planets?

    A. When I was choosing my PhD topic, I knew that SPHERE was about to be commissioned. I was really excited by the instrument and liked the idea of spending time in Chile working with it. I also thought it would be interesting to look at protoplanetary disks, which are much easier to detect than planets. Disks are 40% polarised, whereas planets are just a few per cent polarised, so disks are a great target for the polarimetric observing mode. Also, observing disks gives us really beautiful images with a lot of structure. We can say a lot about the system just by looking at the image, which is something I find really exciting!

    Q. Earlier this year you won the Olivier Chesneau Prize which is co-established by ESO. What did winning this prize mean to you and how has it enabled you to continue doing great work?

    A. It’s a very nice confirmation that my work contributed something to the field! It’s wonderful to have your peers tell you that your thesis was worthy of such a prize. It also gave me some visibility; I went to the awards ceremony, where I presented my work and got some media attention, which brought the research to people who would probably never have seen it otherwise.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

     
  • richardmitnick 8:53 am on September 20, 2019 Permalink | Reply
    Tags: "A date with a formidable science machine", , , , , ESOblog   

    From ESOblog: “A date with a formidable science machine” 

    ESO 50 Large

    From ESOblog

    20 September 2019

    1
    On the Ground

    ESO’s Very Large Telescope (VLT) is the world’s most advanced optical and infrared astronomical observatory and observes objects four billion times fainter than the naked eye can see. But what is it like to spend a night deep in the Atacama Desert observing the stars with the VLT? How does it feel to control such a machine? Cyrielle Opitom, an ESO Fellow resident in Chile, describes one of her shifts observing the night sky with this formidable machine.

    2
    Cyrielle Opitom

    15:00, 21 August 2019

    My workday starts at 3 pm, after a quick breakfast and a visit to the gym. I use one of the observatory cars to drive from the astronomers’ hotel — the Residencia — up to the control room, which is located next to the telescopes and allows us to control them remotely. Contrary to what people might think, the astronomers at Paranal Observatory don’t always work entirely at night. Several of us actually work partly during daytime and partly during nighttime. This allows us to work on projects related to the instruments hosted on the telescopes here, assist visiting astronomers, or prepare observations for the coming night, for example.

    Tonight, we have a visiting astronomer coming to observe with the Very Large Telescope’s (VLT’s) ESPRESSO instrument for the first part of the night. When I arrive at the control room, I make sure that everything is ready for the visitor’s observations, and have a look at what could be observed during the second part of the night, when we will work in service mode, performing observations on behalf of astronomers not present at Paranal. In total, about 60–70% of the observations are made in service mode, and about 30–40% in visitor mode.

    Tonight, I am in charge of the VLT’s third Unit Telescope — UT3, also known as Melipal. At the moment, the UT3 is equipped with only one permanent instrument: SPHERE. However, ESPRESSO can be used with any VLT Unit Telescope, and is often used with UT3.

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

    ESO/ESPRESSO on the VLT, installed at the incoherent combined Coudé facility of the VLT. It is an ultra-stable fibre-fed échelle high-resolution spectrograph (R~140,000, 190,000, or 70,000) which collects the light from either a single UT or the four UTs simultaneously via the so-called UT Coudé trains

    16:00

    At 4 pm, I go to the daily meeting with the various engineering teams (mechanics, electronics, optics, IT, software…). During the meeting, we discuss the state of all the telescopes and instruments to make sure that they are ready for the night and we also plan for the next day.

    After the meeting, it is already time to go back down to the Residencia for some dinner before the night starts. Days are short in winter! After dinner, I head back to the control room.

    18:33

    It’s sunset time! There is never a boring sunset here at Paranal.

    19:00

    Now that it’s dark, it’s time to start observing. To operate the telescope and the instruments, we are sitting at the UT3 console, inside the control room. In general, we need two people to operate one telescope: one astronomer and one Telescope and Instruments Operator (or TIO). The astronomer is in charge of selecting the observations, operating the instrument, and assessing the quality of the data, while the operator is in charge of the telescope itself. Tonight is a bit special and there are four of us at the telescope. I am the support astronomer, Nestor is the TIO, Rosita is a new astronomer-in-training, and we have a visiting astronomer. In visitor mode, the visiting astronomer decides what they want to observe, and the astronomer and TIO execute the observations and check the quality of the data.

    3
    The VLT Unit Telescope 3 console, from which astronomers control the telescope and its instruments.
    Credit: ESO/Cyrielle Opitom
    The screens on the left of the image allow us to control the telescope and are operated by Nestor. In the centre, you can see the control panels for the SPHERE instrument, while ESPRESSO’s are on the right.

    Tonight, we are observing several stars using ESPRESSO to try to detect or characterise exoplanets around them; ESPRESSO is specialised at hunting for rocky exoplanets. The observations are short, so that approximately every 30 minutes we command the telescope to point in another direction to observe a different star. The instructions on how to execute the observations are prepared by the visitors, and stored in what we call an “observing block” using dedicated software. We then use another piece of software to send the instructions to the telescope and instrument system and execute them in sequence. Being in the control room, it is very easy to forget that you are controlling such a large telescope. But every time I remember this, I feel both excited and amazed by the fact that I am the one observing with the VLT.

    21:00

    4
    Cyrielle admires the night sky above one of the VLT Auxiliary Telescopes.
    Credit: ESO/Cyrielle Opitom

    I decide to go out onto the platform to admire the sky and the telescopes before the moon rises. The beauty of the night sky and the Milky Way never fails to amaze me. While the observations are being taken, and after checking the quality of the data obtained so far, we do some observatory-related projects.

    22:00

    It is 10 pm, and after several hours of hard work, it is time for a break. The cooks have brought some snacks into the control building meeting room, so we eat some bread, cheese, ham and fruit to give us the energy we need to get through the rest of the night.

    00:45

    The second part of the night has now started and we are in service mode. It’s getting late, but fortunately we have the coffee machine to help us stay awake for a few more hours!

    In service mode, we use a dedicated tool to decide which of the numerous observations requested by astronomers around the world (and approved by a committee) are most suitable to perform depending on the weather conditions. For now this is another ESPRESSO observation.

    01:30

    We are now changing to the other instrument that we can use with the UT3 telescope: SPHERE. This instrument allows us to correct for atmospheric turbulence — which scatters light and makes images blurry — so that we can obtain the best possible images for a telescope of this size. SPHERE is often used to search for exoplanets, or to image disks around protostars. While performing the observations, I keep training Rosita on how to operate UT3 at night.

    03:00

    Finally my long day/night ends, and it is time to go to bed. Nestor, our TIO, will continue the observations of the night together with Rosita. Only 12 hours to go until my next shift starts!

    5
    Cyrielle (right) and astronomer-in-training Rosita (left) controlling the VLT’s SPHERE instrument.
    Credit: ESO/Cyrielle Opitom

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

     
  • richardmitnick 2:48 pm on September 6, 2019 Permalink | Reply
    Tags: astronomer, , , , , ESOblog, Trystyn Berg   

    From ESOblog: “Cosmic lighthouses” 

    ESO 50 Large

    From ESOblog

    1
    Science@ESO

    6 September 2019

    As an ESO Fellow in Chile, Trystyn Berg uses our telescopes to answer big questions about the Universe. We catch up with him to find out more about his research, what he loves about being an astronomer, and what it’s like to observe the night sky from the Atacama Desert.

    2
    Trystyn Berg

    3
    The Cat’s Paw Nebula is revisited in a combination of exposures from the MPG/ESO 2.2-metre telescope and expert amateur astronomers Robert Gendler and Ryan M. Hannahoe. The distinctive shape of the nebula is revealed in reddish puffy clouds of glowing gas against a dark sky dotted with stars.

    The image was made by combining existing observations from the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile (see ESO Photo Release eso1003) with 60 hours of exposures on a 0.4-metre telescope taken by Gendler and Hannahoe.

    The resolution of the existing 2.2-metre MPG/ESO telescope observations was combined (by using their “luminance” or brightness) with the colour information from Gendler and Hannahoe’s observations to produce a beautiful combination of data from amateur and professional telescopes. For example, the additional colour information brings out the faint blue nebulosity in the central region, which is not seen in the original ESO image, while the ESO data contribute their finer detail. The result is an image that is much more than the sum of its parts.

    The well-named Cat’s Paw Nebula (also known as NGC 6334) lies in the constellation of Scorpius (The Scorpion). Although it appears close to the centre of the Milky Way on the sky, it is relatively near to Earth, at a distance of about 5500 light-years. It is about 50 light-years across and is one of the most active star formation regions in our galaxy, containing massive, young brilliant blue stars, which have formed in the last few million years. It is host to possibly tens of thousands of stars in total, some of them visible and others still hidden in the clouds of gas and dust.

    Q. Could you start off with an overview of what you are working on at ESO?

    A. My research focuses on understanding how and why galaxies change across cosmic history; not all galaxies were born at the same time, and we see a large variety of life stages when we look into the distant Universe. Galaxies contain lots of gas in and between all their stars, and this gas is the life essence of the Universe. So I am mostly trying to figure out how galaxies process gas and how that affects their evolution.

    Alongside my research, I am also one of the support astronomers for the second Unit Telescope of the Very Large Telescope (VLT) at Paranal Observatory. As a support astronomer, I work with the telescope operator to ensure the telescope is capable of performing the requested observations within the ambient weather conditions to push the system to its scientific limits.

    In between observations or during the day, I write software and test the instruments to make sure the telescope-instrument system operates at its best. ESO Fellows can also choose to provide technical support for one or two instruments as an Instrument Fellow, which gives us an in-depth, more hands-on experience with the amazing ESO instrumentation. I am fortunate to be one of the instrument fellows for the VLT’s ESPRESSO instrument.

    ESO/ESPRESSO on the VLT,installed at the incoherent combined Coudé facility of the VLT. It is an ultra-stable fibre-fed échelle high-resolution spectrograph (R~140,000, 190,000, or 70,000) which collects the light from either a single UT or the four UTs simultaneously via the so-called UT Coudé trains

    Q. So how would you summarise your research in one question?

    A. The one question would be: “How can signatures in the gas of galaxies be used to understand galaxy evolution?”

    Q. Why do you think this topic is important?

    A. Stars are born out of cold gas, they process their gas while evolving within a galaxy, and then release this processed gas back into the Universe when they die. This means that the life cycle of stars and galaxies depends on the amount and types of gas they have in their nearby reservoir. And if a significant amount of gas is removed from a galaxy, new stars can no longer form, so the galaxy grows old and “dies”. Since we don’t understand the details of how galaxies stop forming stars, it’s important to look at their gas content which is very sensitive to the underlying astrophysics of galaxy evolution.

    Q. How exactly do you find out more about the gas in galaxies?

    A. I look at bright and distant quasars to sample all the gas between us and the quasars, most of which is in and around galaxies. As a quasar’s light passes through the gas, each element from the periodic table absorbs light at specific wavelengths. This leaves a “fingerprint” on the quasar light we observe that tells us how much of each element there is in the intervening gas. It also tells us about other things, like the temperature and bulk movement of the gas within the galaxy. I try to match up these measured quantities with theories of physical and chemical processes in galaxy evolution, to answer questions like: “what do the first stars look like?” or “how much gas is available to form stars over cosmic time?”

    Chasing ‘hidden’ galaxies (artist’s impression)
    4
    Artist’s impression showing a galaxy located between an observer on Earth and a background quasar that acts as a beacon. The light that travels from the quasar is intercepted by the foreground galaxy on its sightline, carrying out the galaxy’s signature all the way to the observer. The sketch shows a side-on view of the system. The inset shows a face-on view of it, the same view captured (albeit with less detail) by the images taken with the SINFONI instrument on ESO’s Very Large Telescope.

    ESO SINFONI installed at the Cassegrain focus of UT3 on the VLT

    Q. And how and why are you using ESO telescopes to do this?

    A. As quasars are so faint, I rely on large telescopes with very sensitive spectrographs that split light up to accurately measure these gas abundances. ESO’s VLT is one of the largest optical telescopes on Earth and has two amazing spectrographs that provide a unique view of quasar light, so I get most of my data from them.

    X-Shooter is a very sensitive spectrograph that covers a large range of wavelengths. This gives us a lot of information about where the gas is in the Universe, both in space and time (the further it is from Earth, the further back in time we are looking), and what the gas is made of.

    ESO X-shooter on VLT on UT2 at Cerro Paranal, Chile

    Once I have the data from X-Shooter, I use the much higher resolution UVES spectrograph to follow up on the most interesting gas reservoirs, to precisely measure the amounts of specific elements, for example carbon, iron, zinc or oxygen. This allows me to try to answer specific questions, for example what exactly the very first stars were made of.

    UVES spectrograph mounted on the VLT at the Nasmyth B focus of UT2

    Q. Have you found out anything ground-breaking or surprising so far?

    A. One of the current hot topics in astronomy is understanding how certain galaxy evolution processes prevent later star formation. One of these processes is the relatively quick growth of the massive black holes at the centre of some galaxies. Whilst the black hole grows, the environment surrounding it emits lots of energy. This should heat up the gas, causing it to escape from galaxies that would otherwise form stars.

    During my PhD, I used the Hubble Space Telescope to look at light from quasars to probe the nature of the gas surrounding galaxies hosting this active black hole growth, expecting to find the gas either removed or heated up because of the black hole. However, we found a surprisingly large amount of cooler gas instead. It’s not completely clear what causes this, but we suspect that this cooler gas came from a galaxy evolution process that also started the black hole growth (such as a large surge in the amount of star formation, like a starburst), or that these types of galaxies are in gas-rich regions of the Universe.

    Q. Does your work require you to spend much time onsite at Paranal Observatory? What is it like to work and sleep in the Atacama Desert?

    A. I live in Santiago, the capital of Chile, and travel to Paranal about once a month to support not just UVES, ESPRESSO and X-Shooter but also the FLAMES spectrograph.

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

    In the Atacama Desert, where the telescopes are situated, it is very hot during the day from the direct sunlight, and dry all the time; together with the red-coloured mountains this makes it feel like living on Mars!

    Fortunately, the lack of humidity doesn’t affect my sleep (partly because my home town is very cold and dry in winter so I’m somewhat used to dealing with dry environments). However, there is always some effective “jet lag” when changing from regular day-life to astronomer night-life, which takes some getting used to every trip. This affects my sleeping schedule, as well as how well I am able to think late into the night!

    Q. What made you want to become an astronomer?

    A. Growing up, I always had an affinity for maths and science, but it wasn’t until reading and watching 2001: A Space Odyssey and doing some follow-up research up on Saturn and Jupiter and their moons that I became fascinated with Europa and its potential to host life. After that, I wanted to study astronomy and geophysics at university; and in the end astronomy won out.

    Q. What is your favourite thing about being an astronomer?

    A. I enjoy the challenge of finding different ways to approach unknown questions, and designing methods to properly address those questions. In astronomy, the galaxy evolution processes are typical much longer than a human lifetime, so we have the additional challenge of designing observational experiments to studying events that are effectively frozen in one instance of their lives.

    Q. What five words would you use to describe the life of an astronomer?

    A. This may be a bit cliche, but I would say: investigating, programming, googling, communicating, and demanding.

    Biography Trystyn Berg

    Originally from Edmonton, Canada, Trystyn did all of his post-secondary education at the University of Victoria, getting his PhD in 2018 under the supervision of Dr. Sara Ellison. Throughout his studies (particularly as an undergraduate), Trystyn gained experience working at various observatories and has been involved with software development for several upcoming instruments, something he is hoping to build upon at ESO. When not working, Trystyn always seems to end up curling, hiking, golfing, or just playing board games at home.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

     
  • richardmitnick 11:14 am on August 23, 2019 Permalink | Reply
    Tags: , , , , ESOblog, This summer ESO held its first ever Summer Research Programme giving seven talented university students the opportunity to undertake a six-week long research project at ESO Headquarters.   

    From ESOblog: “From comets to cosmology” 

    ESO 50 Large

    From ESOblog

    1

    23 August 2019
    People@ESO

    This summer, ESO held its first ever Summer Research Programme, giving seven talented university students the opportunity to undertake a six-week long research project at ESO Headquarters. Each student worked on a different project, each of which covered a unique area of astronomy — from comets to cosmology. After six weeks packed with new experiences, new networks and new friendships, we speak to the students to find out how they felt about the programme, and what new knowledge and skills they will take back to their home countries.

    2
    Samuel discovers that Cepheid Variable star X Sagittarii shows some strange variability patterns. Together with his advisor, he investigates what physical processes must be causing this.
    Credit: ESO/M. Zamani

    Name: Samuel Ward
    Nationality: British
    University: Durham University, United Kingdom
    Project: Modulated variability: a new window into stellar pulsations

    Q. What was the best part of the summer school for you, and why?

    A. Being part of an active research environment has been such a unique experience and very different to usual university life. The debate and discussion after a presentation or talk on cutting edge astronomical discoveries gives an incredible insight into the scientific process; answers aren’t always known and opposing ideas clash, but you can see how it all shapes our growing understanding of the cosmos. Contributing to this atmosphere, even for only a summer, has been such a privilege and it has made me excited to continue my academic career as I look into PhD positions for next year.

    Q. What memory stands out from the summer school?

    A. One thing I really appreciated was how friendly and welcoming all the advisors, Fellows and Students at ESO were. We were encouraged to make the most of our time in Munich and experience all that the region has to offer. My favourite memory was going hiking in the Alps with the other summer students ⁠— the route was longer than expected, but the views were absolutely spectacular.

    3
    Aisha shows her advisors her new discovery of some of the most distant ultra-diffuse galaxies ever observed.
    Credit: ESO/M. Zamani

    Name: Aisha Bachmann
    Nationality: German
    University: Ruhr Universität Bochum, Germany
    Project: Understanding the formation mechanism of galaxies at their (ghostly) extremes

    Q. What did you enjoy most about the summer school?

    A. It’s hard to choose one thing, but I think meeting so many new people and working on a very interesting research project were definitely the best. Even if at some points in the project work was going slowly and frustration levels rose, solving problems and seeing the result was definitely worth it. The whole working atmosphere at ESO was amazing and I’m really glad I got to have this experience.

    Q. How will you use the knowledge and experience you’ve gained this summer in the future?

    A. The experience, knowledge and skills I gained in the Summer Research Programme will be super useful for upcoming research projects: first of all, my master thesis. Especially working with astronomical software I hadn’t used before is an extremely helpful skill for future projects. Additionally gaining insight into many different research areas and topics through the lectures is helping me determine in which area I’d like to work later on in my career.

    4
    In preparation for using the world’s biggest eye on the sky — the Extremely Large Telescope — Tania creates simulated observations of distant galaxies. She shows her advisors what they will look like when observed through the telescope.
    Credit: ESO/M. Zamani

    Name: Tania Sofia Gomes Machado
    Nationality: Portuguese
    University: University of Lisbon, Portugal
    Project: Preparing for the Extremely Large Telescope : how will high-redshift star-forming galaxies appear with HARMONI ?

    Q. What skills have you gained and developed over the course of the summer school?

    A. I believe the most correct answer to this would be that my programming, data analysis and presentation skills have become so much better. However, that is the pretty picture, the real answer doesn’t sound so worthy of a CV!

    The truth is, I have learned the ups and downs of scientific research; I have learned how to interpret ugly graphs, and to take some real scientific information out of them even though in desperation they didn’t seem to carry any information at all; I have learned that sometimes not detecting any source in the data can actually be a good result (one that even my advisors were not expecting!); I have accepted that every astronomer sometimes gets stuck, or that code doesn’t work, or that data makes no sense, and in those times, spending ten minutes asking for help is better than spending five hours getting nowhere; I have learned that sometimes one starts the day with certain questions and ends up answering completely different questions. That is the not-so-pretty picture, but it has in fact made me a better student and astronomer.

    Q. What was the most important thing about the summer school for you?

    A. I think the most important part for me was the feeling of belonging. By this I mean the feeling of being part of a nice community of scientists, all with different career paths and specifications. I remember each day waking up and telling my housemate what was so exciting about the day ahead! For example, Tuesdays were Lunch Talk (which meant pizza after a great presentation), Wednesdays meant Board Games Club in the afternoon, Fridays were Journal Club day, and so on. Every morning, at 10:30 there was Science Coffee, and even though all of us were working on something important at that time, we would push each other to take that break and have a coffee with other amazing astronomers. This feeling of belonging to the ESO community, and belonging to it together with six other students that were in the same situation, was indeed unforgettable.

    Please visit the full article for four more stories of a summer at ESO Headquarters.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

     
  • richardmitnick 12:26 pm on August 9, 2019 Permalink | Reply
    Tags: , ESOblog, Ivo Saviane - Site Manager since 2013.   

    From ESOblog: “A string of domes in the desert” 

    ESO 50 Large

    From ESOblog

    1
    9 August 2019 People@ESO

    La Silla became ESO’s first observatory when it opened in 1969. Since then, the majestic gathering of telescopes in the Chilean desert has led to an enormous number of scientific discoveries, with on average 300 refereed publications attributed to La Silla telescopes every year. To mark the 50th anniversary of the observatory, we find out what it takes to run such an impressive place from Ivo Saviane, who has been Site Manager since 2013.

    1
    Ivo Saviane

    Q. Could you begin by telling us what you love or what inspires you about La Silla?

    A. The very existence of La Silla as a string of domes in the middle of the Atacama Desert is just incredible, but I also wonder at the extraordinary science that has been (and is still being!) carried out here. For example, two La Silla telescopes were used to find the most remote gamma-ray burst, the observatory played a key role in the Deep Impact campaign, the ESO 3.6-metre telescope was used to find potentially-habitable exoplanet Proxima b, and the TRAPPIST-south telescope was used to detect planets around TRAPPIST 1.

    And because La Silla hosts telescopes and instruments spanning five decades, there is a huge amount of history here. This allows me to set more recent ESO achievements in good evolutionary perspective.

    Q. So what does a typical day in your life as La Silla Site Manager look like?

    A. My main role is to be the hub of an incessant information flow, which happens mostly by email, but also through meetings and daily encounters with staff — for example coffee breaks are a valuable way to keep an eye on observatory life! Input is received through these channels, and most of the time follow-up actions are triggered.

    Many actions are recurring and plannable but others are a consequence of the complex dynamic nature of an observatory: safety concerns arise, the weather can get nasty, people become sick, visitors might be delayed or not arrive, instruments and telescopes can suffer a myriad of technical hiccups, transportation vehicles can break down, staff leave and must be replaced, training activities must be organised, hardware is imported and exported, requests are received to install new facilities on site, etc.

    Some of these issues can be solved internally but often help is required from across ESO. In addition, some actions must be coordinated with other observatories, for example fighting light pollution, maintaining access roads, and exchanging instrumentation. This means it’s vital to maintain good relationships with competing facilities in Chile.

    My typical day thus consists of processing emails, holding internal meetings, contacting other partners, and deciding on actions to be carried out. These might not sound like the most interesting tasks, but they are vital for La Silla to continue to be such a productive observatory.

    Q. This year is the 50th anniversary of the inauguration of La Silla. How has La Silla changed over the time that you have known it?

    A. My first time at La Silla was in 1993, when I arrived at the New Technology Telescope (NTT) for an observing run. This was only four years after its inauguration as “The Best Telescope Yet”, as Sky & Telescope put it on the cover of their September 1989 issue. The NTT marked the peak of La Silla’s golden age, but in 1987 the ESO Council had already decided to build the Very Large Telescope (VLT), likely on the Paranal mountain. It was then natural that focus and resources would move away from La Silla, so the observatory went through a series of reductions in scope.

    ____________________________________________
    An observatory with no resident astronomers is something rather unusual, and at that time the change sparked some outrage in the astronomical community.
    ____________________________________________

    But since then, the biggest change I witnessed was in 2009, when the La Silla 2010+ scheme was inaugurated: among a number of changes, the decision was made not to have support astronomers on site to help visitors during their observing runs or carry out observations in so-called “service mode”. An observatory with no resident astronomers is something rather unusual, and at that time the change sparked some outrage in the astronomical community. However, over time people have become accustomed to it and complaints about missing scientific support are very rare these days.

    The drastic reduction in staff after 2009 means that now only a few people inhabit an urbanised site meant for a much larger population. This might conjure up scenes from a science fiction film, but the remaining staff must have continuous direct interaction with each other in order to keep the place running, so team spirit has strengthened. Besides, with so few people, everyone’s had to develop skills beyond their original experience, which can make daily work more interesting.

    One might also remark that astronomy has moved away from the kind of individual or small group efforts that dominated during most of the last century. An ever-growing mass of data, and the need to gather them over the whole spectral range and resolution, has triggered a trend where it is now more likely that high-impact papers are the results of large collaborations. In this context it is good to see a steady flow of young and enthusiastic researchers populating the La Silla control room every night.

    ____________________________________________
    I personally think that La Silla’s smaller telescopes could survive only by joining forces and eventually establishing a worldwide network.
    ____________________________________________

    The future of La Silla depends on the will of ESO and its community to keep operating the observatory’s two main telescopes; the NTT and the ESO 3.6-metre. In the upcoming age of 10-metre and 40-metre optical-infrared telescopes I personally think that La Silla’s smaller telescopes could survive only by joining forces and eventually establishing a worldwide network. But at the moment we are expecting two new instruments — SOXS for the NTT and NIRPS for the ESO 3.6-metre telescope — and several new hosted projects are about to start operations. Therefore I expect that the nature of La Silla will not change much in the next decade or so.

    ____________________________________________
    If I had to pick some highlights, the changing natural environment would be at the top.
    ____________________________________________

    Q. What are your most special memories from your time at La Silla so far?

    A. La Silla is such a unique place that all time spent there is somehow special. I think it is no coincidence that, given the choice, most visiting artists in the past selected to stay at La Silla over other ESO sites.

    But if I had to pick some highlights, the changing natural environment would be at the top: the extraordinary view of the flowering desert, when hills turn green and great swaths of magenta flowers appear; the green flash before the sun disappears below a razor-sharp horizon; snow covering the landscape; shadows of clouds on brightly coloured mountains; the occasional rain that fills the air with its scent; herds of guanacos browsing the bushes; majestic condors circling the dome of the 3.6-metre telescope; desert foxes watching you from a distance.

    And over all this sweeps the magnificent night sky. On my first observing run, I had fallen asleep whilst been driven up to the summit after an exhausting journey. As I opened the door of the vehicle and looked up, I almost fell back in awe at the view of the Milky Way shining overhead. I felt overwhelmed by the grandiosity of the sight, but at the same time the urge to understand what was happening in front of my eyes was spurred beyond resistance. It seems impossible that somebody could look at the night sky at La Silla and not have the same feeling!

    ____________________________________________
    I almost fell back in awe at the view of the Milky Way shining overhead.

    3
    A swath of stars appears to cut the New Technology Telescope in two. The majestic telescope enclosure aligns perfectly with the Milky Way’s central region.
    Credit: ESO/B. Tafreshi (twanight.org)
    ____________________________________________

    But back to Earth, it takes some special characters to adapt to such an unusual lifestyle, where you work and live with the same people in a confined place for several days in a row. Thus inevitably, memorable conversations and stories come alive, so some of my best memories are related to these aspects of the social life at La Silla. In particular I remember fondly the midnight meals shared with visiting and support astronomers from all around the world. The dimly lit dining room helped create a feeling of sharing and good spirit, and life experiences were shared from different cultural backgrounds, enriching everybody’s souls.

    Q. La Silla is home to a large (and growing!) number of telescopes. Do you have a favourite?

    A. In the past, I spent many nights as an observer or support astronomer working with the NTT, so that is high on my list. However my dearest memory rests with the MPG/ESO 2.2-metre telescope: in September 1996 I was there observing a dwarf galaxy in the constellation of Phoenix, and I was hoping that the new EFOSC2 detector, with its better response in the blue part of the spectrum, would allow me to resolve a special class of stars that are key to inferring the age of a stellar population. At that time we were still observing in control rooms inside each telescope building, so I launched very long exposures and went out to look at the sky.

    I could see the open dome slit and the top ring of the telescope pointing towards “my” galaxy, as it slowly tracked the motion of the stars, making a subtle hum, which was interrupted every few minutes by a metallic sound coming from the dome as it changed position. These visual and acoustic impressions seemed to announce that the secrets of the galaxy would soon be revealed to me, and I felt almost at one with the instrument and the night sky. You can imagine my excitement when I could see those stars in the data, which sealed that September night into my memory.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

     
  • richardmitnick 1:07 pm on July 12, 2019 Permalink | Reply
    Tags: "The mystery of the darkening sky", , , , , ESOblog, Solar Eclipses through history   

    From ESOblog: “The mystery of the darkening sky” 

    ESO 50 Large

    From ESOblog

    12 July 2019
    On the Ground

    2

    On 2 July 2019, a solar eclipse passed over part of South America, temporarily bringing an eerie darkness to ESO’s La Silla Observatory in Chile. It was a once-in-a-lifetime opportunity for many to view an eclipse from a unique spot. But eclipses were not always viewed as the wondrous spectacles that they are today. They were once bad omens, foreshadowing terrible events and instilling fear in those who saw them.

    3
    The path of the 2019 solar eclipse. Observers within the central red line saw a total solar eclipse, whilst those further from the path of totality saw a partial solar eclipse. Credit: OpenStreetMap contributors, timeanddate.com

    Just about 2000 years ago humans came to understand that a solar eclipse occurs when the orbit of the Moon causes it to pass exactly between the imaginary line connecting Earth and the Sun. When this happens the Moon blocks the light from the Sun, casting a shadow onto the Earth, which moves across Earth’s surface as it rotates.

    Solar eclipse expert and ESO photo ambassador Petr Horálek explains, “A total eclipse happens because although the Sun is about 400 times further from the Earth than the Moon, its diameter is 400 times larger. This means they appear the same size in the sky so the Sun is almost perfectly blocked by the Moon. The really amazing thing about this is that a total solar eclipse gives us the chance to see the Sun’s corona — the outer layer of its impressive atmosphere. And if that wasn’t enough, there are many breathtaking phenomena to be seen in the moments before and after the Moon completely blocks the Sun”.

    The recent solar eclipse at La Silla Observatory lasted more than two hours, with the Sun being completely covered by the Moon for almost two minutes. Over 1000 visitors travelled to La Silla from around the world hoping to get a glimpse of the spectacle. Skies were clear, giving astronomers the opportunity to use the observatory’s world-class telescopes to observe the eclipse for outreach and science purposes, following a long tradition of taking advantage of eclipses for scientific research.

    4
    Composed of several images taken during the total solar eclipse at La Silla, this image highlights Bailey´s Beads, a feature visible only at the very beginning and the very end of totality. Baily´s Beads are caused by the Moon´s mountains, valleys, and craters creating an uneven edge of the Moon, where small “beads” of sunlight still shine through the lowest parts for a few moments after the rest of the Sun is covered.
    Credit: ESO/P. Horálek

    65
    An image of the Sun during the total solar eclipse visible from ESO’s La Silla Observatory on 2 July 2019 at the moment when most of its face is occulted by the moon. The eclipse lasted roughly two and a half hours, with almost two minutes of totality, and was visible across a narrow band of Chile and Argentina. To celebrate this rare event ESO invited 1000 people, including dignitaries, school children, the media, researchers, and the general public, to come to the Observatory to watch the eclipse from this unique location. Credit: ESO/M. Zamani

    The recent eclipse inspired awe and wonder in all who were lucky enough to see it, but before the phenomenon was well-understood, eclipses were mysterious and often terrifying events. “People are scared of what they don’t understand, and what could be more confusing and frightful than suddenly being shrouded in darkness,” Petr says.


    A video of the total solar eclipse visible from La Silla Observatory on 2 July 2019. Credit: ESO/R. Lucchesi

    6
    Babylonian Solar Eclipse Tablet listing eclipses between 518 and 465 BCE. Credit: NASA

    The earliest eclipses were documented on clay tablets and cave walls, with the very first written record coming from China in 2137 BCE. According to traditional astrological theories, the Sun was the symbol of the Chinese Emperor and so eclipses in China stood as imperial warnings.

    Petr explains further: “In Chinese culture it was believed that eclipses were caused by a hungry dragon devouring the Sun. The record from 2137 BCE describes two royal astronomers, Chi and Ho, who had not warned others about the eclipse and were too drunk to fulfil their task of beating a drum to scare away the dragon”.

    It wasn’t until almost 1500 years later that the Greek philosopher Thales of Miletus accurately predicted a solar eclipse, according to ancient Greek historian Herodotus. If Herodotus’s account is to be believed, the Eclipse of Thales is the earliest recorded that had been foreseen in advance, even though eclipses were still not understood at the time. How exactly Thales predicted the eclipse remains uncertain it is possible that he knew about the periodicities of eclipses, that he was able to calculate it or that he just made a lucky guess! Horálek explains: “Nowadays it is easy to predict future solar eclipses. They follow a strict periodicity and can be predicted with mathematical calculations that consider the position of the Moon in relation to the Sun. Astronomers can do it for thousands of years into the future!”.

    Running these calculations in reverse, many historians believe that the Eclipse of Thales was the solar eclipse of 28 May, 585 BCE. Interpreted by Herodotus as an omen, it interrupted a battle in a long-standing war between the Medes and the Lydians. The fighting stopped immediately, and they agreed to a truce.

    6
    The treaty of Verdun led to the Carolingian empire being split into three regions (shown here in pink, green, and yellow.
    Credit: Wikimedia commons

    Some historical eclipses are still shrouded in mystery. Reports from both Christians and non-Christians of the death of Jesus describe a period of daytime darkness. Some historians believe this could have been caused by a solar eclipse, but bewilderingly, the crucifixion supposedly took place during the Jewish festival of Passover, which is celebrated during a Full Moon. A solar eclipse can only occur during a New Moon. Furthermore, present-day astronomers believe that the only two eclipses to have occurred near the time of the crucifixion were closer to Antarctica and Australia — it seems unlikely that either was visible from Jerusalem!

    It wouldn’t be an exaggeration to say that solar eclipse events may have even changed the course of history. Louis the Pious, son of Charlemagne, was head of the Carolingian empire when he witnessed a solar eclipse on 5 May 840 CE. According to legend, it terrified him so much that he died shortly afterwards. His three sons then began to dispute his succession. After three years of debate, the quarrel was settled with the Treaty of Verdun. This treaty divided Europe into three large areas which indirectly led to present day France, Germany and Italy.

    Three hundred years later in 1133 CE, King Henry I of England died shortly after he observed a solar eclipse. William of Malmesbury wrote in the manuscript Historia Novella that the “hideous darkness” agitated the hearts of men. After the death, a struggle for the throne threw the kingdom into chaos and civil war.

    8
    The first successful photo of a solar eclipse, clearly showing the corona — the upper layer of the Sun’s atmosphere. Credit: Wikimedia commons

    Whilst historical figures were shocked by eclipses, by the seventeenth century physicists began using them to investigate the Sun scientifically. The first accurate and scientifically useful photo of an eclipse was taken in 1851 at the Royal Observatory in Königsberg. To take this photo, daguerreotypist Johann Julius Friedrich Berkowski exposed a copper plate directly to the Sun’s light through a small refracting telescope, capturing an 84-second exposure which for the first time allowed scientists to study the Sun’s corona long after totality had passed.

    Eight years later, German physicist Gustav Kirchhoff figured out how to analyse light from the Sun and the stars to deduce their chemical composition. Scientists eagerly awaited the next solar eclipse, which would allow them to study the chemistry of solar prominences. In 1868, the opportunity finally arose. French astronomer Pierre Jules César Janssen camped out in India to watch the Moon pass in front of the Sun, revealing brilliant solar prominences. Like other Sun-gazers that morning, Janssen discovered that the prominences were mostly made of hot hydrogen gas, as was expected. But he also used a spectroscope to discover something intriguing — yellow light was present that didn’t match the wavelength of any known element. Further studies led him to discover that this line was actually produced by Helium, named after “Helios”, the Greek personification of the Sun. And thus Helium was discovered on the Sun before it was discovered on Earth.

    9
    This image was taken by the ESA–CESAR team of scientists at the total solar eclipse visible from ESO’s La Silla Observatory on 2 July 2019. It was made by combining multiple polarised images of the solar corona during totality to bring out the details in its structure. Credit: ESA/CESAR

    When Albert Einstein published his general theory of relativity in 1915, he proposed three critical tests to prove it, one of which was that light should be deflected by a gravitational field. This phenomenon could be investigated by measuring whether light from distant stars is diverted by the gravity of the Sun. Just before the total solar eclipse of 1919, Sir Arthur Eddington took nighttime measurements of the positions of the Kappa Tauri double star in the Hyades cluster. During the eclipse, the Sun crossed Kappa Tauri, and the starlight became visible. Comparison of the stars’ normal positions and the corresponding positions detected during the eclipse showed that light was indeed deflected when it passed close to the Sun. Einstein’s world-changing theory was proved to be correct!

    Eddington/Einstein exibition of gravitational lensing solar eclipse of 29 May 1919

    Past eclipses have helped us make many scientific discoveries, but still today mysteries remain that astronomers hope to solve by observing the Sun during future eclipses.

    Petr tells us: “In 1869 astronomers William Harkness and Charles August Young captured spectra of the solar corona and found a mysterious new element there. Eventually people discovered that this “new element” was in fact iron that had been ionised 13 times! But this discovery brings with it a bigger mystery; such strong ionisation can only occur in places with temperatures of millions of degrees. The temperature of the corona cannot be this high, so the big question is: where and how does this ionisation occur and how do the ionised elements move to the corona? This is still the greatest coronal mystery”.

    9
    This image of the solar corona was taken by an ESA–CESAR team of scientists during the total solar eclipse visible from ESO’s La Silla Observatory on 2 July 2019. It clearly shows bright red prominences — places where loops of glowing plasma flow up from the Sun’s surface. The path of this plasma, composed of hydrogen and helium, is probably determined by the Sun’s magnetic fields, which can twist and tangle in strange ways. We know that prominences can persist for weeks or even months, but we don’t fully understand why they exist or what their internal dynamics are. This is why continuing research into the Sun’s complex atmosphere is important, much of which can only be done during total solar eclipses. Credit: ESA/CESAR

    Solar tornadoes, vortices of magnetic turbulence that swirl up from the surface, might be to blame. So too may be deeper, magnetic tsunamis within the sun, transferring their heat outward.

    “Observations during future eclipses could help settle the issue between the two, or reveal another unexpected cause,” Petr continues. “Moreover, solving this mystery and getting a better understanding of upper solar atmospheric physics could allow us to better predict space weather in the future, potentially saving a lot of money, and even lives.”

    “Watching a total solar eclipse is so amazing and unique that your breath is taken away in the first few seconds of the show. The Sun looks like it has frozen. Nature, confused by the darkness, goes to sleep, and the excitement of people is incredible. After you’ve seen it once, you can’t wait to see it again!”

    See the full article here .


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

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

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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

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

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

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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level


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

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

     
  • richardmitnick 1:03 pm on June 28, 2019 Permalink | Reply
    Tags: Astronomical site selection, , , , , ESOblog   

    From ESOblog: “Home sweet home” 

    ESO 50 Large

    From ESOblog

    How to decide where a telescope should spend its life.

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

    28 June 2019

    As soon as a new telescope gets the green light to be developed, it’s time to find it the perfect home. This is no easy task, as different environmental conditions can have a huge effect on the quality of observations a telescope can make. We speak to Marc Sarazin and Julio Navarrete of ESO’s Site Survey Team, who were involved in testing sites for both the Very Large Telescope (VLT) and the Extremely Large Telescope (ELT).

    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,

    Q. Firstly, can you tell us a bit more about your role here at ESO?

    Marc Sarazin (MS): I was hired back in the eighties to help choose a site for the ambitious Very Large Telescope (VLT), and I still work in telescope site selection today! In reality this means working with other staff and local contractors to decide on the best place for a telescope to be located. We gather lots of information about a site before the final site selection committee — which is made up of astronomers representing the scientific communities within ESO’s Member States — makes a final decision about which one is best.

    Julio Navarrete (JN): And I started at ESO’s Paranal Observatory in Chile two years after Marc started at Headquarters. I worked on site testing full time until the VLT began operating, then moved to science operation with 15% of my time dedicated to site monitoring. Before I joined ESO I was working in oil exploration; I completely changed perspective, from looking down to looking up at the sky!

    Q. What would you say are the most important criteria to consider when choosing on an astronomical observing site?

    MS: There are so many aspects to consider. Some of these, like clouds, wind, and altitude, impact the science a telescope is able to carry out. We constantly monitor the turbulence in the air above the observatories, because we want the air to be as still as possible, to minimise the blurring of light from the Universe as it travels through Earth’s atmosphere. But we also need to consider other more practical factors like cultural issues, building and maintenance costs, and ease of access to the site.

    Then there’s geology. It’s easier and cheaper to build on solid rock than sand, for example, and telescopes are very sensitive to earthquakes, so an earthquake-free zone is a bonus. Low temperatures can also pose problems because they cause the lubricant oil in telescopes to freeze. And we want to avoid dusty areas because dust landing on the mirrors can damage reflective coatings. With so many factors to consider, it takes a very long time to test and select a site!

    JN: We are also careful not to disturb animal populations too much, so ecological studies are carried out by independent institutes. For instance, when choosing a site for the ELT, we discovered that some desert mice lived on the preferred site. Fortunately there weren’t too many, so we didn’t consider it too detrimental.

    The important thing to note is that it’s impossible to find a perfect location with no problems at all. We always need to weigh up the advantages and disadvantages of each site, and finally work towards a compromise.

    2

    Testing Cerro Armazones for the Very Large Telescope. Marc and Julio with Chilean observers working on meteorology and cloud spotting. It looks pretty windy; the afternoon was always blustery but the nights were much calmer.
    Credit: Marc Sarazin/ESO

    Q. Can you walk us through the process of testing a site?

    MS: We start by using satellite observations to identify many large areas that could be suitable for a site, scientifically speaking. We eliminate some for political or safety reasons, and are typically left with three or four. Then we look for specific candidate sites within each area, for example dry summits with low levels of light pollution. And nowadays, as most people do before they go on holiday, we also tend to have a look around on Google maps before visiting the sites in person.

    For example, when choosing a site for the VLT, in South America we narrowed the choice down to Argentina and Chile. Both countries have lots of summits — just beautiful! — but there is also a lot of mining, so we needed to find somewhere far from the mines to avoid vibrations and dust. We set up dedicated robotic stations at sites across both countries, which took measurements for several years before we could make a decision. For the VLT, we also tested Gamsberg in the Namib Desert and checked sky conditions at Reunion Island.

    JN: Whilst site testing for the VLT, I had to stay onsite in a caravan with just a driver and a cook for several months at a time! This was during the eighties, when we didn’t have such independent robotic equipment, so it took more human effort to make measurements at a site. I was in charge of operating the testing instrument, diagnosing and repairing failures, and cleaning the dishes after meals.

    For the VLT, it took seven years in total to select Cerro Paranal to be its future home, with about five of these involving site testing. Testing for this long ensures that we are confident about site conditions, and are sure that we are not just testing the site in a fluke year with particularly superb conditions. But Cerro Paranal is truly excellent, with very little rain or cloud cover, wonderful conditions to carry out science, and virtually no light pollution.

    Q. And more recently you were both involved in selecting a site for ESO’s Extremely Large Telescope (ELT). Was it difficult to choose a home for the world’s “largest eye on the sky”?

    MS: Even though the ELT is huge, choosing a site for it was actually no more difficult than for the VLT, because the ELT is just one single telescope whereas the VLT is made up of four large Unit Telescopes.

    4
    Testing Cerro Armazones in 2009 for the Extremely Large Telescope.
    Credit: ESO/G. Lombardi (glphoto.it)

    For the ELT we considered sites in the Canary Islands, Morocco, Argentina and Chile. One committee was set up to analyse the scientific quality of each site based on data we provided, as well as that provided by other site testing groups using the same equipment. Then another committee had the arguably more difficult job of looking into the socio-economic nature of each site, for example political issues, ease of access and cost of construction.

    JN: But before we had come to a final decision, we had a stroke of luck. The American Thirty Metre Telescope (TMT) was due to be built on top of a mountain called Cerro Armazones, very close to the VLT.

    TMT-Thirty Meter Telescope, proposed and now approved for Mauna Kea, Hawaii, USA4,207 m (13,802 ft) above sea level

    We had actually previously considered this site as a potential for the VLT. Cerro Armazones was a wonderful site and would have been an excellent location for the TMT, but in 2009 it was decided that it would make more sense to build the telescope in the US state of Hawaii. This left Cerro Armazones thoroughly tested and now wide open.

    This mountaintop outshone all the other sites we had been looking at, so ESO snapped up the opportunity and decided to build the ELT there. Not only are the weather conditions excellent, but the proximity to the VLT means that a lot of infrastructure, for example roads and a hotel, already existed that we would have otherwise had to build. ESO also already had various agreements in place with the Chilean government, so that simplified things a lot!

    Q. Do you continue to monitor a site whilst science operations are ongoing?

    MS: Yes, we continue to monitor the “astroclimate” even when the telescopes are built and operating, using an on-site meteorological station. We do this so that astronomers can capture the best possible images, to understand the performance of the instruments and to better-plan observations. For example if we monitor a site for several years, we can predict which months are better from a scientific point of view. We can plan difficult observations during those periods, and schedule maintenance during the worst months.

    And because of climate change, some parts of the world are changing faster than others. The stability of a telescope site is really important, so we do look at how conditions change over a longer period of time. We know that the Atacama Desert, for example, has been a desert for hundreds of years, but there are cycles in the clouds. When we were first monitoring the site, about 15% of nights were cloudy. As time went on, this percentage steadily increased, and now it’s steadily decreasing again. This is a cycle that lasts about 30 years.

    Q. Do you think astronomical sites will be chosen in the same way in the future, or will technological advances change the process?

    5
    At the top of Cerro Armazones, the site of the ELT. On the right is the Differential Image Motion Monitor (DIMM), used to measure the atmospheric seeing. The white and red tower to its left is the meteorological station.
    Credit: F. Char/ESO

    MS: There was already a huge difference between choosing a site for the VLT and choosing one for the ELT. For the VLT we were using paper satellite photographs to study cloud cover, whereas for the ELT we had big databases based on meteorological models. We now have meteorological data with a resolution of just a couple of kilometres, compared to 40 kilometres in the eighties.

    We also now have information about the historical weather at a site, meaning that we don’t need to spend months or years checking the weather conditions. We do, of course, still need to investigate geology, whether we would be disturbing animal populations, and more practical issues like how easy it will actually be to build a telescope there.

    JN: But overall, now we spend a lot more time monitoring sites remotely from our offices than actually staying on the site itself. This is sad for me, because my favourite part of my job is to be out in the field, even if that means being the designated washer-upper!

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

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

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


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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

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

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

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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level


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

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

     
  • richardmitnick 1:13 pm on June 14, 2019 Permalink | Reply
    Tags: "Spot-on Science", , , , , , ESOblog, Paola Amico-Science Liaison   

    From ESOblog: “Spot-on Science” 

    ESO 50 Large

    From ESOblog

    Why all ESO Supernova content is checked by an active scientist.

    1
    The very first panel of the exhibition The Living Universe in the ESO Supernova Planetarium & Visitor Centre, explains why we study the Universe. From here, visitors will be taken on a journey all the way across the Universe, learning about stars, galaxies, black holes, exoplanets and much more. Credit:ESO/P. Horálek

    The ESO Supernova is the gateway to space for the European public. It provides an immersive experience that leaves visitors in awe of the Universe in which they live and seemingly-abstract concepts are explained in an innovative and engaging way. But all this is futile if we don’t get the science right. We speak to ESO scientist Paola Amico about her involvement as a “Science Liaison” for the ESO Supernova.

    2
    Paola Amico

    Q. Firstly, could you tell us what being a Science Liaison for the ESO Supernova involves?

    A. I check everything that is produced for scientific accuracy to make sure that people are as well informed as possible and that misconceptions are not spread. This all started in 2016, when there was a call for volunteers for the ESO Supernova, which was due to be opened to the public two years later.

    I applied and Tania — the Supernova Coordinator — realised I had a background in astronomy. She checked my CV to review my experience and quickly asked me to take on the role of Science Liaison! I happily accepted and continue to do this even now. It means that I evaluate the text on everything that is produced in the Supernova; this includes exhibition panels, student workshops, planetarium shows, and even the AstroCalendar, which is a kind of database of astronomical events. At the same time, I also took on the role of Science Liaison for ESO’s Department of Communications more generally.

    Q: What experience do you have that makes you a good Science Liaison?

    A: By background I am an astronomer specialising in galactic dynamics — so how galaxies rotate, dark matter and things like that. After finishing a PhD in astronomy, I started at ESO as a Fellow in 1994, and somehow I got more and more attracted to the technology that is applied to astronomy. In particular I became fascinated by detectors, which are a bit like the eyes of any telescope.

    I was later offered a fellowship in ESO’s instrumentation division, and from that moment on I managed to stay in the field of technology for astronomy. I worked as an instrument scientist and support astronomer for eight years, both at Keck Observatory and at ESO’s Paranal Observatory. My instruments were almost all capable of adaptive optics, which corrects for turbulence in Earth’s atmosphere that causes stars to twinkle and blur. Telescopes that use adaptive optics are really cool, and I think even more fun than other telescopes! Somehow it requires some real-time thinking, interacting and interpretation, because the atmosphere changes all the time, making it quite human-like. I would say working on instruments with adaptive optics is now my role of expertise, I am a systems engineer and I support two instruments on ESO’s Extremely Large Telescope.

    I’m very lucky, because I’m pretty old (ha!) and saw many astronomical technologies being born. The application of technology to astronomy was really starting to take off when I began working in the field. With detectors, for example, they were first one pixel, then eight, and now we are working with detectors made up of millions of pixels! It’s been a real privilege to see that happen and I think working in astronomy during this time of change has given me vital knowledge that I can apply to my Science Liaison role.

    As well as explaining current science and astronomy, the ESO Supernova also presents ESO and all the incredible telescopes that we operate. For example, I was involved in developing a workshop all about optics that shows students and teachers how instruments work and what people can do even with small telescopes. I think my experience in astronomy technology really gives me a broad range of knowledge in the “what”, “why” and “how” of astronomy that makes me a good fit for the Science Liaison role.

    Q: The ESO Supernova covers pretty much every topic in astronomy. Has it been difficult to review such a range of subjects?

    A: It was a bit overwhelming at the beginning! Even for active astronomers it can be a challenge to know the most up-to-date research in every area. For me, this was partly why I wanted to be involved — to get back in touch with all of astronomy. And I’ve learned so much! I went through all my studies again and began recovering all this information.

    The interesting thing is that when I started as an astronomer back in the eighties, the science was at a completely different stage. Since then astronomy has progressed an almost unbelievable amount and there have been so many incredible discoveries. There is so much modern science that is hugely important now that we knew little about twenty years ago; take black holes, gravitational waves, and dark energy for example. I’m so pleased to have had the opportunity to catch up on some of the things I missed — but it required a lot of hard work!

    Of course, when reviewing content for the ESO Supernova, I have to check that all the numbers and facts are reported correctly, and in order to do that I cross-check and read a lot of scientific papers. It is so important that all our information is accurate, because it is our duty to inform the public.

    Q: What excites you most about the ESO Supernova?

    A: The reason I volunteered in the first place was to give tours to the students, in particular secondary school students, given my past as a high school maths teacher. I love interacting with them and telling them all about astronomy and science. When I first started at ESO, I volunteered with Italian kids, guiding them around the ESO Headquarters and even showing them a movie about the construction of ESO’s Very Large Telescope. This was really exciting — even watching a movie was very spectacular back then!

    We always put time aside for the students to ask astronomers questions, and I just loved that. But now, with the Supernova, I am supported by a hugely impressive exhibition, making it easier to impress the public, much more than I did just with just a VHS back in 1994!

    Q: What is your favourite thing about being a Science Liaison at ESO?

    A: Astronomy is intrinsically wonderful, with every image being so beautiful and impressive. But I love to be able to explain that there is so much more behind the beauty, and using that to inspire young people to go into science, or just to ask big questions and think about their place in the Universe.

    Science is about solving a mystery, and it’s great to give people a sense of the scientific approach — I like to encourage people to question what’s around them and maybe even to be more critical about what they might hear in the news.

    With the Science Liaison work, I always think critically. I take everything I read a sentence at a time, looking at each word and asking if this is the best word to use, the best way to describe an idea. I look at everything with doubt, not because I don’t trust what someone has written, but because it helps you critically analyse what you are looking at, and make it better.

    See the full article here .


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

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


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

    ESO VLT 4 lasers on Yepun


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

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

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

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

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


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

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

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

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

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level


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

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

     
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