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  • richardmitnick 6:59 am on January 18, 2020 Permalink | Reply
    Tags: "Five minutes with Andreas Kaufer", , , , , , ESOblog   

    From ESOblog: “Five minutes with Andreas Kaufer” 

    ESO 50 Large

    From ESOblog

    17 January 2020
    People@ESO

    1
    Andreas Kaufer

    ESO’s Director of Operations talks maps, mops and modern technology

    From late nights studying sky maps with his grandfather to late nights leaving parties to make observations. From building small instruments for telescopes himself to being part of the construction of the biggest eye on the sky. Andreas Kaufer talks about how astronomy has changed during his career, along with the challenges ahead as the field continues to advance.

    Q. What about astronomy first piqued your interest?

    A. My grandfather was a big fan of world maps and the last page of world atlases at that time always had a map of the stars. So, one evening, when I was a kid we were looking at the sky and he had one of his big atlases out and we were trying to understand what this white light in the sky was. We couldn’t figure it out because it wasn’t on the map. Eventually, we found out it was a planet which doesn’t appear on a paper map because its position is always changing. We were curious and got some books to read about it and that’s how I first became interested in astronomy. Shortly after I joined a nearby amateur observatory.

    But I saw astronomy as a hobby at first, and it was not actually my goal to be a professional astronomer. I only returned to astronomy at the end of my physics studies.

    Q. So how did you come back to astronomy?

    A. I studied Physics in Heidelberg, Germany, where there was a heavy focus on particle physics. The Large Hadron Collider at CERN was really taking off at the time and many of us were getting into particle physics and working on the big experiments there. But there was the option to do an astronomy practicum at the observatory in Heidelberg — so I got back into astronomy.

    2
    Cutting through the turbulence
    The biggest obstacle in ground based astronomy is the same thing that causes the stars to twinkle — the atmosphere. This romantic effect is due to the distortion of light as it travels through turbulent gases to reach the Earth’s surface. This stunning image shows the scientific solution — the 4 Laser Guide Star Facility on ESO’s Very Large Telescope (VLT) [see also below] — here appearing to pierce the side of the Milky Way. The lasers form an integral part of the adaptive optics system on the VLT, by beaming artificial stars into the sky. Astronomers can then use these guide laser stars as reference points, allowing them to correct their observations of true celestial bodies. Credit: F. Kamphues/ESO

    I did some stellar atmosphere modelling work on the university’s mainframe computers at a time when this was quite a new thing. At the same time I got into observations because we had some monitoring programmes there at night at the observatory on the Königstuhl. It’s not the best site but when the weather was clear and the city below was under clouds we could observe. But the downside was that when I was on-shift and the weather was clear, I would have to leave parties and movies to go to the observatory in the middle of the night!

    Building instruments was my favourite thing. At the amateur observatory, we had to build instruments ourselves because we couldn’t afford to buy such equipment. I was lucky to be able to do it later on a big scale. First at the observatory in Heidelberg, and then later here at ESO where we build instruments on a very big scale, so it’s a dream come true to be here!

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

    A. In the Directorate of Operations we take care of the scientific operation of all of ESO’s facilities; this includes all the telescopes and instruments which are built by the organisation and in collaboration with institutes and the industry in our Member States. We maintain the telescopes and instruments at their best possible performance and run the whole system from preparing and executing the observations with our telescopes to delivering the processed data to the scientists. For many observations the scientist do not go to observe onsite anymore but we take their observation at the best possible time for them.

    Q. What are some of the most rewarding aspects of the job?

    A. For me, the big eye-opener coming to ESO was seeing what all the other scientists are doing. Academia and institutes are usually focused on small areas of science, so people (like me) coming from there are often only exposed to a specific part of astronomy. Then arriving at the observatories, one sees all these ideas; we review about a thousand research proposals to use the telescopes every six months and whilst not all of them are accepted, we see ideas from all areas of ground-based astronomy. Due to my current role, I don’t participate in huge projects anymore, but for me, the reward is to see other people pushing forward diverse and innovative research using ESO facilities.

    The satisfaction somehow (which I think is true for many people at ESO) is to enable research. You feel part of these discoveries even if you did not do the science or the analysis yourself. But the telescope and instrument worked in the right way at the right time to get the best possible observations. That for me is still and always will be the motivation: to enable.

    4
    Andreas Kaufer mops up a leak from the VLT’s SINFONI instrument. Credit: ESO

    Q. And some of the strangest?

    A. There is a picture of me with a mop under one of the big telescopes, mopping up some water dripping out of the instrument.

    We had a huge leak in a cooling line inside the VLT’s SINFONI instrument. Everybody had to rush, me included, to clean up otherwise the cooling liquid would destroy the oil film on which the telescope rotates. For me this was a natural thing to do, so I was surprised when people were later showing this picture around saying “look the Director has been mopping the telescope!”

    Q. What are the challenges you see for the next generation of scientists and engineers in astronomy?

    A. As for scientists, we already see that they are becoming more and more disconnected from the data collection by the telescopes, as they often stay at home whilst observatory staff collect the data. Modern scientists are very good at using data from whichever telescopes help them answer their questions, be they space- or ground-based. Given this, we need to ensure that we keep understanding the scientists’ needs, and that we keep adjusting to meet them.

    For the engineers, the world of technology is changing very rapidly. At ESO we are already quite advanced in many areas but not in others, so we need to keep an eye open to the advancements happening around us. At Paranal Observatory, we’re working with technologies from when the VLT [below] was built, from the 80s and 90s. The Extremely Large Telescope (ELT) [below] — currently under construction — will use much more modern technology. The challenge for our engineers at the observatory is to make this bridge between the different generations of technology and master them all. Those are what I would see as the two big challenges for ESO: Trying to keep our scientific community engaged and staying at the forefront of technology so that we can achieve the best quality science.

    Q. What are you looking forward to in astronomy over the next ten years?

    A. We are all fascinated by the idea of making progress in the search for life elsewhere in the Universe! But a more realistic goal is continuing our search for exoplanets and to advance on the analysis of their atmospheres.

    [Didier Patrick] Queloz and [Michel] Mayor recently together received the 2019 Nobel Prize in Physics for discovering the first extrasolar planet orbiting a solar-type star, which they found just when I first got into professional astronomy. This was really an eye-opener. We knew that there must be planets around other stars but when they observed the first one, it was like science fiction becoming reality! That kicked off a whole new field of astronomy and, one generation later, we’ve discovered several hundred planets with our instruments at La Silla Observatory [below]. Furthermore, the VLT has taken many images of planets around stars other than our Sun, and in the next ten years we will be able to use the ELT to look for traces of life in their atmospheres.

    A few years ago now, APEX [below] opened up the submillimetre window for the ESO community; at the time we were not sure where submillimetre astronomy would go but now the ALMA [below] partnership is an integral part of ESO. Today, ALMA is the most powerful submillimetre observatory and perfectly complements the most powerful optical observatory on the ground — the VLT.

    I’m also looking forward to ESO’s partnership with the Čerenkov Telescope Array (CTA) Observatory. CTA will be an observatory made up of an array of many telescopes that allow us to observe the sky at very high energies by capturing gamma-rays. And ESO will host the southern part of this observatory again opening up a new window to the ESO community!

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

    See the full article here .


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    Please help promote STEM in your local schools.

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

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

    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 APEXESO/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft)at the Llano de Chajnantor Observatory in the Atacama desert.

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

     
  • richardmitnick 4:44 pm on December 6, 2019 Permalink | Reply
    Tags: , , , , , ESOblog, Katja Fahrion,   

    From ESOblog: “Astronomer on tour” 

    ESO 50 Large

    From ESOblog

    The story of a trip to Chile to observe with the APEX telescope [below]

    6
    Katja Fahrion

    6 December 2019
    People@ESO

    Measuring a whopping twelve metres across, APEX is a submillimetre-wavelength telescope operating in the southern hemisphere and has a suite of instruments to find out more about the “cold”, “dusty” and “distant” Universe. APEX is operated by ESO on behalf of the Max Planck Institute for Radio Astronomy, the Onsala Space Observatory and ESO itself, meaning that many ESO astronomers get to spend time at the telescope each year. ESO Student Katja Fahrion tells us about her recent experience observing with this special machine.

    DAY ONE: MOVING IN

    The first day of my two-week observing trip to the Atacama Pathfinder EXperiment (APEX) began at 4 am on 22 August 2019 in the ESO Guesthouse in Santiago, Chile. After a quick breakfast, a taxi took me to the airport and at 9 am I was in Calama, in the Atacama Desert. A driver picked me up and after about an hour of driving through the desert, I arrived at the APEX basecamp, close to San Pedro de Atacama.

    APEX is a submillimetre telescope, observing at millimetre and submillimetre wavelengths — between infrared light and radio waves, from a variety of astrophysical sources. It consists of a single dish with a diameter of twelve metres, located on the Chajnantor Plateau (the same plateau where ALMA resides!) 5100 metres above sea level. Unlike optical telescopes that only operate at night, submillimetre telescopes can also observe when the Sun is up.

    So when I arrived at the basecamp at around 11 am, the morning observing shift was still ongoing. For the first time, I entered the control room — the heart of the basecamp. One wall is covered with screens showing the status of the telescope, the output of the live webcam and the weather conditions, and the other walls are lined with desks and even more screens.

    Observers at APEX and other ESO telescopes don’t observe their own science targets, but instead carry out the observing programmes that are proposed by scientists from all around the world. At all times, at least one operator and one observer are present in the control room. While the operator is responsible for operating and controlling the telescope, the observer decides what to observe. The latter is my job as an astronomer and in the beginning, it seemed overwhelmingly complex.

    1
    Centre of the Milky Way with Jupiter and Saturn, taken by Katja during her APEX observing trip.
    Credit: ESO/Katja Fahrion

    I moved into my hut that contained a small desk, a bed and a bathroom. Since it gets very cold in the desert at night, each room also has several radiators and the beds are covered with blankets.

    Besides the huts and the control room, there are office spaces, a kitchen where breakfast, lunch and dinner are served, a recreational room including a table tennis table and a rowing machine, and a swimming pool. The swimming pool, that I used almost every day, has a beautiful view of the Sairecabur volcano. During the night, this volcano is not visible, but the view is replaced by the beautiful southern night sky.

    DAY TWO: IN THE CONTROL ROOM

    Although I got a brief introduction on the first day, I spent most of my second day at APEX in the control room learning how to observe with the telescope.

    One specific parameter the observers have to keep in mind is the precipitable water vapour (PWV) describing the amount of water vapour in the atmosphere above the telescope. Because water absorbs electromagnetic radiation at the wavelengths we want to observe, it is critical to have low values of PWV, just like you would not want clouds over your optical telescope. A PWV of 0.4 mm is absolutely great, 0.7 mm is still very good, there are some programmes that can work with 1.5-3 mm, but basically above 4, there is not much to be done and above 6 the telescope is shut down.

    Besides PWV, the wind speed is also shown in the control room because if it is too windy, the telescope has to be shut down and parked in a safe position. And then there is the Sun. Although APEX can observe during day, it cannot be pointed at or near the Sun because the antenna would focus the light and all the cables and instruments would melt. This is clearly something that we wouldn’t want to happen!

    ___________________________________
    I felt the lack of oxygen as soon as I arrived; getting my backpack from the boot of the car was already exhausting.
    ___________________________________

    I learned that it is essential to keep a record of everything that happens during an observation. We use a webpage where the records for every observing programme can be accessed and updated. This is important for the person that proposed the programme in the first place, but also for the APEX observers working different shifts.

    DAY THREE: I CAN GO UP!

    On my third day at APEX, I got the opportunity to go to the telescope site in the morning with another student and two engineers. This meant driving up the hill from 2300 metres to 5100 metres above sea level. Although the drive is through the desert, on the side of the road, I saw cacti, bushes, donkeys, birds and vicunas.

    Up at the telescope, the air is thin and has only half the pressure it has at sea level. I felt the lack of oxygen as soon as I arrived; getting my backpack from the boot of the car was already exhausting. I felt a bit weak and dizzy in the first few minutes, so I was happy to enter the control room that is supplied with extra oxygen.

    While the two engineers worked on the telescope generators, the other student and I spent some time in the control room to acclimatise. But soon the excitement won, and we went out to take pictures of extraordinary sight up on the Chajnantor Plateau. In the distance, I could see the 66 ALMA antennas under a clear blue sky, surrounded by volcanoes.

    Going up to the telescope was not the only exciting event on this day. Every Saturday, the Asado takes place. Everyone gathers at the kitchen and even the observers and operators bring their laptops to observe remotely. There are drinks and many different foods such as deep-fried cheese empanadas, ceviche and small sandwiches. There is also a barbeque with lots of beef and sausages. Music plays and after dinner the party carries on in the kitchen or around the fireplace.

    DAY FOUR: I GET TO OBSERVE

    On the fourth day of my stay at APEX, I carried out observations during the evening shift for the first time on my own. During the previous days, I had become accustomed to the different observing programmes and roughly knew the weather constraints and priority of observing targets on the sky. Due to Earth’s rotation, the targets move in the sky and can only be observed when they are high enough above the horizon. So it is important to know which programme can be observed at any time of the day. This has to be balanced against the weather conditions and the priority of the programme, but after a few days of watching other observers making decisions, I was able to continue with ongoing projects.

    DAY FIVE: VISITING A LAGUNA

    At the beginning of my stay, there were at least four observers at any time, so shifts lasted six hours instead of the typical eight hours. This meant that we had a lot of free time, especially as I was not yet on the official schedule. So on 26 August, another student and I drove to the nearby Laguna Chaxa. An hour’s drive from the basecamp, this Laguna is known for its beauty and an impressive flock of flamingos.

    3
    Two flamingos having a drink at Laguna Chaxa. Credit: ESO/Katja Fahrion

    DAYS SIX AND SEVEN: FIRST OFFICIAL SHIFTS

    On 27 August, I began my (almost) regular shift schedule of 5 pm to 11 pm. On this day and the next, I had quiet shifts because the weather was not great. We observed a very time-intensive programme with the instrument PI230 that can be used even when there is a lot of water vapour in the air. We created maps of a molecular gas cloud in our own galaxy, the Milky Way. Because molecules such as carbon monoxide form at very low temperatures, they are not visible with optical telescopes. With submillimetre telescopes like APEX, however, we can observe bright spectral lines at a very specific wavelength and can thus observe the source. With telescopes such as APEX it is possible to either observe a single spectrum or to create a small map of a region in the sky that shows the structure of a source emitting at a certain wavelength. In both modes, it is also important to observe a reference position in the sky to remove unwanted background emission from Earth’s atmosphere. Sometimes the reference position is contaminated by other astronomical light and this is one of many reasons why the observer has to look at the data while they are being taken.

    4
    Large and Small Magellanic Clouds above the antennas that are used for communication between basecamp and the APEX telescope.
    Credit: ESO/Katja Fahrion

    DAY EIGHT: THE NIGHT SHIFT

    My first and only night shift was from 10 pm to 4 am. During this night, the weather conditions were very good at first, so we used the ArTeMiS instrument that requires the best conditions to create beautiful maps of astronomical sources. Later, we switched to SEPIA. Switching the instrument requires some time, so it’s best not do it too often. After my night shift, I was very tired, but I took the opportunity to take some pictures of the night sky.

    DAY NINE: TIME TO SLEEP!

    After my night shift I slept in. The weather was not great again, so during my shift in the evening, we made more maps with PI230. It was a relaxing shift that gave me time to work on my own projects.

    DAY TEN: UP TO THE TELESCOPE AGAIN

    On the second Saturday of my stay, I had the opportunity to go back up to the telescope. Even the second time, the visit was exciting. On the way, we saw llamas and several Vicunas that were very close to the road. My shift was during the Asado, but I could still spend some time with the others in the kitchen, enjoying empanadas and the barbecue.

    ___________________________________
    I would get up, have breakfast, work on my PhD project and go swimming. In the evening, from 5 to 11 pm, I was in the control room doing my shift.
    ___________________________________

    DAYS ELEVEN TO FOURTEEN: GETTING INTO A ROUTINE

    Only a few days of my shift at APEX were left and by then I was used to the routine. I would get up, have breakfast, work on my PhD project and go swimming. In the evening, from 5 to 11 pm, I was in the control room doing my shift. The weather was at first very good for observing with the most demanding instruments but then it got worse and we even had to close the telescope for an hour one night due to strong wind. The sunsets during these last days were beautiful because for the first time, there were clouds in the sky.

    On my last full day, 4 September, another observer from ESO and I visited the nearby Valle de la Luna. We were rewarded with astonishing views of an alien-looking landscape — similar to the surface of Mars or the Moon!

    DAY FIFTEEN: NEXT STOP — ANTOFAGASTA AND THE VERY LARGE TELESCOPE [below]

    After 13 nights at the APEX basecamp, it was time to leave. I had finished my last shift the day before, and after lunch, the driver brought me to the bus terminal in Calama. From there I took a four-hour bus ride to Antofagasta, 300 kilometres southwest of San Pedro. The next day, an official ESO bus took me to my two-night stay at the Very Large Telescope. Not to work, but just to visit.

    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
    ESO/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft)at the Llano de Chajnantor Observatory in the Atacama desert.

     
  • 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.

    2
    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-

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    ESO Bloc Icon

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

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

    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.

    4
    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 .


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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.

     
  • 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 .


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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.

     
  • 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

     
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