Tagged: Adaptive Optics Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 4:11 pm on October 8, 2018 Permalink | Reply
    Tags: Adaptive Optics, , , , , Excitation of sodium atoms in the mesosphere creates an artificial point of light at a precise known location and elevation, Laser guide star systems, Laser Guide Stars Measure Geomagnetism,   

    From Optics & Photonics: “Laser Guide Stars Measure Geomagnetism” 

    From Optics & Photonics

    08 October 2018
    Stewart Wills

    1
    Polar mesospheric clouds. [Image: NASA]

    Laser-created “guide stars” form a key part of the adaptive-optics (AO) techniques that have revolutionized astronomy, by setting up ways for ground-based telescopes to see through atmospheric distortions.

    ESO VLT 4 lasers on Yepun

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

    In work published this year, several research groups have found another use for these laser-induced artificial lanterns: pinning down the shape and intensity of Earth’s magnetic field at a scientifically crucial—and, previously, largely inaccessible—range.

    Wobbling beacons

    In AO techniques using guide stars, a powerful laser adjacent to a ground-based telescope zaps a small piece of Earth’s middle atmosphere, or mesosphere, 85 to 100 km above the telescope. The consequent excitation of sodium atoms in the mesosphere creates an artificial point of light at a precise, known location and elevation. That winking light source, in turn, gives the telescope operators on the ground a known point to grab onto, and lets them computationally cancel out (via wavefront-shaping techniques) the turbulence in the lower atmosphere. The result? A sharper view of the stars beyond.

    In 2011, scientists led by James Higbie of Bucknell University, USA, suggested that laser guide stars for AO might also function as tiny, remote magnetometers for measuring Earth’s mesospheric magnetic field [PNAS]. The approach would work through measurements of the precession, or wobbling, of the laser-excited sodium atoms in the magnetic field.

    More specifically, as the circularly polarized laser beam excites the sodium atoms, it also spin-polarizes them, which causes them to wobble like spinning tops in the magnetic field. The frequency of that precession, which depends on the local field strength, can be read via changes in the fluorescence signal captured by a ground-based detector.

    Such measurements, if they could be made to work, would prove a nice win for geophysics. That’s because the mesosphere occupies a difficult-to-access middle zone between space-based and ground-based measurements of the magnetic field. Yet understanding that elusive part of the field is crucial to a complete picture of overall geomagnetism, for scientific applications ranging from plate tectonics to ocean circulation to space weather.

    In May of this year, a group of U.S. researchers finally put the idea of using wobbling laser guide stars as magnetometers to the test (Journal of Geophysical Research). The team fired a 1.33-W laser to excite mesospheric sodium atoms, and then gathered the backscattered guide star light with a 1.55-m-aperture telescope. By measuring the precession, they were able to obtain a value of the field consistent with several models “within a fraction of a percent.” But the method’s sensitivity, at 162 nT/Hz½, fell considerably short of the level of around 1 nT/Hz½ thought to be necessary for useful measurements of mesospheric magnetic-field variations.

    In work published at the end of September, scientists from Germany, Italy, Canada and the United States reported a significant improvement on that accuracy (Nature Communications). They aimed a continuous-wave laser from the European Southern Observatory’s laser guide star unit adjacent to the William Herschel Telescope on La Palma, Canary Islands at the mesosphere, delivering roughly 2 W of laser power to the sky.

    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.

    The team then captured the received light with a 40-cm-aperture telescope mounted on the AO system’s receiver control unit. The received light, after passing through a photomultiplier tube, was then sent to a digital signal-processing stack for backing out the precession from the fluorescence signal, and for tuning the laser to reduce scintillation noise from the atmosphere.

    2
    A team of scientists from Germany, Italy, Canada and the U.S. used a ground-based laser developed for astronomical adaptive optics, equipped with an acousto-optical modulator (AOM), to excite sodium atoms in the mesosphere. Ground-based measurement of the optical signal was used to estimate the precession of the spin-polarized sodium atoms and, thus, of the Earth’s magnetic field in that area. [Image: F.P. Bustos et al., Nature Communications]

    Boosting sensitivity

    By focusing on a narrower resonance frequency in the precession signal, the international team reported, the researchers were able to achieve accuracy of 0.28 mG/Hz½ (28 nT/Hz½)—“an order of magnitude better sensitivity” than the U.S. team’s result early in the year, albeit still below the ultimate 1-nT/Hz½ target. The international group suggested that the results could be improved still further; using higher laser powers, for example, would allow researchers to boost the number of atoms interrogated by the method, sharpening sensitivity.

    The researchers also noted an interesting side-effect of the recent work. By digging into the details of resonance frequencies tied to the excited sodium atoms’ spin-relaxation rate, they were able to suss out information on the rates of atomic collisions in the mesosphere. Getting such quantitative information on collisional dynamics, the team wrote, is “important for the optimization of sodium laser guide stars and mesospheric magnetometers”—and could thus further improve the potential usefulness of these beacons for astronomy and geophysics alike.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Optics & Photonics News (OPN) is The Optical Society’s monthly news magazine. It provides in-depth coverage of recent developments in the field of optics and offers busy professionals the tools they need to succeed in the optics industry, as well as informative pieces on a variety of topics such as science and society, education, technology and business. OPN strives to make the various facets of this diverse field accessible to researchers, engineers, businesspeople and students. Contributors include scientists and journalists who specialize in the field of optics. We welcome your submissions.

    Advertisements
     
  • richardmitnick 1:44 pm on August 3, 2018 Permalink | Reply
    Tags: Adaptive Optics, , , , , , , Frank Eisenhauer,   

    From ESOblog: Advancing Technology for Galactic Observations 

    ESO 50 Large

    From ESOblog

    1
    Science Snapshots

    3 August 2018

    In May 2018, the star S2 made its closest approach to the black hole at the centre of the Milky Way. Observing this event was no easy task. The centre is full of dense dust clouds, impenetrable at visual wavelengths. The unique instruments GRAVITY and SINFONI, able to take highly precise measurements, needed to be developed for these observations. Frank Eisenhauer, a member of the Galactic Centre group at Max Planck Institute for Extraterrestrial Physics and principal investigator for GRAVITY and SINFONI, talks about observing the close approach of S2 in the second of a three blog post series.

    ESO GRAVITY in the VLTI

    ESO SINFONI


    ESO/SINFONI

    Q: Can you tell us a bit about what observations your team aimed to make about the galactic centre?

    A: We knew that the star S2 would make a close flyby of the black hole in the centre of the Milky Way in 2018, making it possible to study the effects predicted by Einstein’s theory of general relativity. We expected the motion of the star to deviate from a Keplerian orbit based on Newton’s laws. Our observations aimed to see these differences, so, to see any visible changes, we had to improve our observation accuracy by several orders of magnitude compared to previous measurements.

    3
    This simulation shows the orbits of stars very close to the supermassive black hole at the heart of the Milky Way. The area is a perfect laboratory to test gravitational physics and specifically Einstein´s general theory of relativity. Credit: ESO/L. Calçada/spaceengine.org

    Q: What did you and your team do to prepare for this year’s observations?

    A: Our instrument — GRAVITY — was finished about three years ago and arrived in Chile, the site of ESO’s telescopes. Then the most intense period started: making GRAVITY work together with all four telescopes of the Very Large Telescope (VLT). In the summer of 2016, we had our first observations of the galactic centre, which, for the first time, showed not only S2 but also the black hole with unprecedented resolution. Since then they have become our faithful companions whenever we visit for a look. For the closest approach in 2018, the team returned for further observations every month.


    Animation of the path that an incoming light ray traces through the GRAVITY instrument. Note the intricate design and complex interaction of the various components for the four telescopes. For interferometry to work, the light paths have to be superposed with a precision of a fraction of the wavelength – less than 1 micrometre.
    Credit: MPE

    4
    The VLTI Delay Lines, which lie below the ground at Paranal, inside a 168-m tunnel. They form an essential part of this very complicated optical system by ensuring that the light beams from several telescopes arrive in phase at the common interferometric focus. Credit: Enrico Sacchetti/ESO

    Q: What kind of telescope did the team use to observe the galactic centre?

    A: So, we needed a “super-telescope”, which we created by combining the four largest ESO telescopes of the Very Large Telescope (VLT) with a technique called interferometry. This technique is well established in radio astronomy, i.e. when observing at longer wavelengths, but many thought it would be impossible to achieve that level of sensitivity and accuracy at infrared wavelengths. And, yes, it was not easy. But the star would not wait for us — and in the end, we were ready in time!

    Q: Can you explain how infrared interferometry works?
    The optical path lengths between the four telescopes and our instrument have to be controlled with the precision of a fraction of the wavelength

    A: With an interferometer, you combine the light received from different telescopes. The big challenge is to combine this light properly, or “in phase” as the physicists say. This means that the optical path lengths between the four telescopes and our instrument have to be controlled with the precision of a fraction of the wavelength—several hundred times smaller than the thickness of a human hair—while the telescopes are separated by as much as 130 metres.


    Learn more about the first successful test of Einstein’s General Theory of Relativity near a supermassive black hole in ESOcast 173.
    Credit: MPE

    5
    Every day, before the observations start, each telescope undergoes a complete start up during which each of its function is checked, like a plane before take off. Here, Yepun, the fourth Unit Telescope, has been moved to a very low altitude, revealing the cell holding its main mirror and the SINFONI integral-field spectrograph. Credit: ESO

    Q: Can you tell us a bit about the ESO instruments used and the differences between them?

    A: The group around Reinhard Genzel at the Max Planck Institute for Extraterrestrial Physics (MPE) started to observe the galactic centre with the SHARP I camera on the New Technology Telescope in the 1990s. At that time, high-quality infrared detectors became available and we were the first to use them to peer through the dust cloud obscuring the galactic centre. Then came NACO with the VLT, which lead to the breakthrough with the first orbit measurement in 2002. In parallel, we developed SINFONI, the first near-infrared imaging spectrograph for the VLT, which has given us crucial velocity measurements since its installation in 2003. And, finally, GRAVITY now combines all four VLT telescope to a “130-m super-telescope.”

    Q: What about these instruments makes it possible to see through the curtain of dust and stars?

    A: The galactic centre is hidden behind dense dusts clouds — but this is only true for visible light. If you go to infrared wavelengths, you can see through to the stars beyond. However, part of this radiation is absorbed by the Earth’s atmosphere, and in particular water vapour in the air. This meant we needed to go to a high place, with less atmosphere above us, and a dry place, i.e. a desert. This is why the Paranal observatory, on top of a high mountain in the Atacama desert, was the perfect place for these observations. But even for the best observing conditions, the atmosphere’s turbulence blurs the images, which is why we need adaptive optics (AO).

    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.

    Q: Can you tell us a bit about the Adaptive Optics system for IR imaging? Are there any challenges using AO to observe the Galactic Centre?

    A: Adaptive optics means that you measure the distortion from the Earth’s atmosphere a few hundred times per second, and correct it in real time with a deformable mirror. For this, you need a bright reference star. Unfortunately, there are no really bright stars at visible wavelengths close to the galactic centre to measure these distortions. Therefore you have two options: create your own artificial star with a laser beacon, as done with SINFONI, or build an infrared wavefront sensor as we did for GRAVITY.

    Q: What advancements in observing technology have made it possible for us to study the galactic centre as compared to 20 or 25 years ago when observations of the galactic centre were really becoming possible?

    A: When the group at MPE started observing the galactic centre in the 1990s, we could observe with 150 milliarcsecond resolution. This is about the angle under which a stadium 300 metres diameter would appear on the Moon. Now, with GRAVITY, we can observe with a resolution as good as 2 milliarcseconds, and measure the separation between the star S2 and the black hole with a precision of just a few tens of microarcseconds. The latter is equivalent to observing two objects on the Moon that are separated by the length of a pencil.

    Q: What do you find most exciting about studying the galactic centre?

    A: To see so many miracles predicted by the general theory of relativity all in one place: the black hole, stars moving at incredible speed, the time dilation, and many other phenomena. The centre of the Milky Way is and will remain our Rosetta stone for deciphering these wonders.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

     
  • richardmitnick 8:01 am on July 18, 2018 Permalink | Reply
    Tags: A new adaptive optics mode called laser tomography, Adaptive Optics, , , , , , , , Narrow-Field adaptive optics mode   

    From European Southern Observatory: “Supersharp Images from New VLT Adaptive Optics” 

    ESO 50 Large

    From European Southern Observatory

    18 July 2018

    Joël Vernet
    ESO MUSE and GALACSI Project Scientist
    Garching bei München, Germany
    Tel: +49 89 3200 6579
    Email: jvernet@eso.org

    Roland Bacon
    MUSE Principal Investigator / Lyon Centre for Astrophysics Research (CRAL)
    France
    Cell: +33 6 08 09 14 27
    Email: rmb@obs.univ-lyon1.fr

    Calum Turner
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: pio@eso.org

    1
    ESO’s Very Large Telescope (VLT) has achieved first light with a new adaptive optics mode called laser tomography — and has captured remarkably sharp test images of the planet Neptune, star clusters and other objects. The pioneering MUSE instrument in Narrow-Field Mode, working with the GALACSI adaptive optics module, can now use this new technique to correct for turbulence at different altitudes in the atmosphere. It is now possible to capture images from the ground at visible wavelengths that are sharper than those from the NASA/ESA Hubble Space Telescope. The combination of exquisite image sharpness and the spectroscopic capabilities of MUSE will enable astronomers to study the properties of astronomical objects in much greater detail than was possible before.

    ESO MUSE on the VLT

    GALACSI Adaptive Optics System for VLT


    ESOcast 172 Light: Supersharp Images from New VLT Adaptive Optics (4K UHD)


    Zooming in on the globular star cluster NGC 6388

    The MUSE (Multi Unit Spectroscopic Explorer) instrument on ESO’s Very Large Telescope (VLT) works with an adaptive optics unit called GALACSI. This makes use of the Laser Guide Star Facility, 4LGSF, a subsystem of the Adaptive Optics Facility (AOF). The AOF provides adaptive optics for instruments on the VLTs Unit Telescope 4 (UT4). MUSE was the first instrument to benefit from this new facility and it now has two adaptive optics modes — the Wide Field Mode and the Narrow Field Mode [1].

    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.

    The MUSE Wide Field Mode coupled to GALACSI in ground-layer mode corrects for the effects of atmospheric turbulence up to one kilometre above the telescope over a comparatively wide field of view. But the new Narrow Field Mode using laser tomography corrects for almost all of the atmospheric turbulence above the telescope to create much sharper images, but over a smaller region of the sky [2].

    3
    These images of the planet Neptune were obtained during the testing of the Narrow-Field adaptive optics mode of the MUSE/GALACSI instrument on ESO’s Very Large Telescope. The image on the right is without the adaptive optics system in operation and the one on the left after the adaptive optics are switched on. Credit: ESO/P. Weibacher (AIP)

    With this new capability, the 8-metre UT4 reaches the theoretical limit of image sharpness and is no longer limited by atmospheric blur. This is extremely difficult to attain in the visible and gives images comparable in sharpness to those from the NASA/ESA Hubble Space Telescope. It will enable astronomers to study in unprecedented detail fascinating objects such as supermassive black holes at the centres of distant galaxies, jets from young stars, globular clusters, supernovae, planets and their satellites in the Solar System and much more.

    Adaptive optics is a technique to compensate for the blurring effect of the Earth’s atmosphere, also known as astronomical seeing, which is a big problem faced by all ground-based telescopes. The same turbulence in the atmosphere that causes stars to twinkle to the naked eye results in blurred images of the Universe for large telescopes. Light from stars and galaxies becomes distorted as it passes through our atmosphere, and astronomers must use clever technology to improve image quality artificially.

    To achieve this four brilliant lasers are fixed to UT4 that project columns of intense orange light 30 centimetres in diameter into the sky, stimulating sodium atoms high in the atmosphere and creating artificial Laser Guide Stars. Adaptive optics systems use the light from these “stars” to determine the turbulence in the atmosphere and calculate corrections one thousand times per second, commanding the thin, deformable secondary mirror of UT4 to constantly alter its shape, correcting for the distorted light.

    MUSE is not the only instrument to benefit from the Adaptive Optics Facility. Another adaptive optics system, GRAAL, is already in use with the infrared camera HAWK-I. This will be followed in a few years by the powerful new instrument ERIS. Together these major developments in adaptive optics are enhancing the already powerful fleet of ESO telescopes, bringing the Universe into focus.

    ESO GRAAL adaptive optics system.

    ESO GRAAL

    ESO HAWK-I on the ESO VLT

    This new mode also constitutes a major step forward for the ESO’s Extremely Large Telescope, which will need Laser Tomography to reach its science goals. These results on UT4 with the AOF will help to bring ELT’s engineers and scientists closer to implementing similar adaptive optics technology on the 39-metre giant.
    Notes

    [1] MUSE and GALACSI in Wide-Field Mode already provides a correction over a 1.0-arcminute-wide field of view, with pixels 0.2 by 0.2 arcseconds in size. This new Narrow-Field Mode from GALACSI covers a much smaller 7.5-arcsecond field of view, but with much smaller pixels just 0.025 by 0.025 arcseconds to fully exploit the exquisite resolution.

    [2] Atmospheric turbulence varies with altitude; some layers cause more degradation to the light beam from stars than others. The complex adaptive optics technique of Laser Tomography aims to correct mainly the turbulence of these atmospheric layers. A set of pre-defined layers are selected for the MUSE/GALACSI Narrow Field Mode at 0 km (ground layer; always an important contributor), 3, 9 and 14 km altitude. The correction algorithm is then optimised for these layers to enable astronomers to reach an image quality almost as good as with a natural guide star and matching the theoretical limit of the telescope.

    See the full article here .


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

    Please help promote STEM in your local schools.


    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

    ESO La Silla HELIOS (HARPS Experiment for Light Integrated Over the Sun)

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

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

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

    ESO VLT Platform at Cerro Paranal elevation 2,635 m (8,645 ft)

    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.

    ESO/NTT at Cerro La Silla, Chile, at an altitude of 2400 metres

    ESO/Vista 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, at an altitude 3,046 m (9,993 ft)

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

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

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

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

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

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

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

     
  • richardmitnick 1:27 pm on May 15, 2018 Permalink | Reply
    Tags: Adaptive Optics, , , , , IFA at Manua Kea U Hawaii Manoa,   

    From U Hawaii IFA at Manua Kea: “Robo-AO” 

    U Hawaii

    From University of Hawaii

    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA
    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA

    1

    From U Hawaii IFA at Manua Kea

    Archived News: 2015-2016

    June 26th, 2016: The Robo-AO team is at the SPIE Astronomical Telescopes and Instrumentation in Edinburgh, Scottland with 4 talks and 2 posters that used Robo-AO data or technology:

    3

    C. Baranec The Rapid Transient Surveyor
    D. Atkinson Next-generation performance of SAPHIRA HgCdTe APDs
    C. Ziegler SRAO: optical design and the dual-knife-edge WFS
    N. Law SRAO: the southern robotic speckle + adaptive optics system
    C. Ziegler The Robo-AO KOI survey: laser adaptive optics imaging of every Kepler exoplanet candidate
    M. Salama Robo-AO Kitt Peak: status of the system and optimizing the sensitivity of a sub-electron readnoise IR camera to detect low-mass companions

    4
    March 9th, 2016 Robo-AO was found to be the second most scientifically productive laser adaptive optics system in 2015 (behind Keck). With the redeployment to Kitt Peak last year, and four papers currently under review, we’re optimistic this productivity will continue well into the future.

    Histogram of refereed science publications from the world’s laser adaptive optics systems.

    Figure adopted from P. Wizinowich (Keck) and used with permission.
    5

    November 12th, 2015 The Robo-AO system has been installed at the 2.1-m telescope at Kitt Peak and we are in the middle of comissioning. For more frequent updates, please see our Robo-AO Facebook page.

    6
    The Robo-AO ultraviolet laser at the Kitt Peak 2.1-m telescope.

    7
    Robo-AO mounted on the Palomar Observatory 1.5m telescope. The adaptive optics and camera systems are in the box mounted on the back end of the telescope. The large box on top of the telescope is the support electronics rack, and the UV laser guide star system is mounted on the bottom of the telescope. Image credit: C. Baranec

    See the full article here .

    Please help promote STEM in your local schools.

    stem

    Stem Education Coalition

    System Overview

    The University of Hawai‘i System includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
  • richardmitnick 5:58 pm on December 18, 2017 Permalink | Reply
    Tags: Adaptive Optics, , , , , , ESO Signs Contract for ELT Laser Sources   

    From ESO: “ESO Signs Contract for ELT Laser Sources” 

    ESO 50 Large

    European Southern Observatory

    18 December 2017
    Frank Lison
    TOPTICA Projects GmbH
    Email: Frank.Lison@toptica-projects.com

    Richard Hook
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    1

    ESO has signed a new agreement with TOPTICA, the German photonics company, for the production of lasers to be used in ESO’s Extremely Large Telescope (ELT) adaptive optics system. TOPTICA [1], in partnership with the Canadian company MPB Communications Inc. (MPBC) [2], will build at least four laser sources for the ELT [3], helping the telescope to achieve unprecedented spatial resolution for an optical/infrared ground-based telescope. The ELT is scheduled to see first light in 2024.

    The laser system for the adaptive optics system on the ELT will be based on the Four Laser Guide Star Facility (4LGSF) on ESO’s Very Large Telescope (VLT). The Adaptive Optics Facility, which uses the 4LGSF, has already shown spectacular improvement in image sharpness on the VLT (eso1724). The TOPTICA/MPBC Guidestar Alliance was the main contractor for the laser system on the VLT (eso1613).

    Adaptive optics compensate for the blurring effect of the Earth’s atmosphere, enabling astronomers to obtain much sharper images. Lasers are used to create multiple artificial guide stars high in the Earth’s atmosphere. These points of light are used as reference light sources to allow the adaptive optics system to compensate for turbulence in the Earth’s atmosphere. Unlike natural guide stars, laser guide stars can be positioned anywhere to allow the full power of adaptive optics to be used over almost the entire sky.

    Anticipated observations enabled by the ELT’s powerful built-in adaptive optics system include everything from studying black holes to investigating some of the youngest galaxies in the distant Universe.

    Notes

    [1] TOPTICA is responsible for the laser system engineering and contributes its diode and frequency-conversion technology. The work will be executed by TOPTICA Projects GmbH, which focuses on specialised laser systems such as laser guide stars.

    [2] The construction of the high-powered Raman fibre amplifiers and fibre laser pump modules will be performed by MPB Communications Inc. of Montreal, Canada. MPBC has a history of providing high power Raman fibre amplifiers for submarine communications and scientific work.

    [3] The ELT is designed to potentially have up to eight laser guide star systems in future.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition
    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

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

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

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

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

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

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

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

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

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

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

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

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

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

     
  • richardmitnick 10:07 pm on December 15, 2017 Permalink | Reply
    Tags: A valuable STEM (Science Technology Engineering and Mathematics) opportunity for education and workforce development, Adaptive Optics, AO is a technique used to remove the distortions caused by turbulence in the Earth’s atmosphere, , , , , High-impact research on the hunt for habitable exoplanets, , The Keck telescopes were the first large telescopes to be equipped with adaptive optics and subsequently laser guide stars, W. M. Keck Observatory Awarded NSF Grant to Boost Performance of Adaptive Optics System   

    From Keck: “W. M. Keck Observatory Awarded NSF Grant to Boost Performance of Adaptive Optics System” 

    Keck Observatory

    Keck Observatory.
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    December 15, 2017
    No writer credit.

    1
    Adaptive optics (AO) measures and then corrects the atmospheric turbulence using a deformable mirror that changes shape 1,000 times per second. Initially, AO relied on the light of a star that was both bright and close to the target celestial object. But there are only enough bright stars to allow AO correction in about one percent of the sky. In response, astronomers developed Laser Guide Star Adaptive Optics using a special-purpose laser to excite sodium atoms that sit in an atmospheric layer 60 miles above Earth. Exciting the atoms in the sodium layers creates an artificial “star” for measuring atmospheric distortions which allows the AO to produce sharp images of celestial objects positioned nearly anywhere in the sky. IMAGE CREDIT: ANDREW RICHARD HARA, http://www.andrewhara.com

    One of the most scientifically productive adaptive optics (AO) systems on Earth is getting a major upgrade, one that will further advance high-impact research on the hunt for habitable exoplanets, the supermassive black hole at the center of the Milky Way, and the nature of Dark Matter and Dark Energy.

    The National Science Foundation (NSF) has awarded funding to the W. M. Keck Observatory on Maunakea, Hawaii for a significant enhancement of the performance of the AO system on the Keck II telescope.

    “The Keck telescopes were the first large telescopes to be equipped with adaptive optics and subsequently laser guide stars. All major astronomical telescopes now have laser guide star AO systems. Despite this competition, Keck Observatory’s AO systems have remained the most scientifically productive in the world. This upgrade will help maintain our science community’s competitive advantage,” said Principal Investigator Peter Wizinowich, chief of technical development at Keck Observatory.

    AO is a technique used to remove the distortions caused by turbulence in the Earth’s atmosphere. This results in sharper, more detailed astronomical images. This upgrade will further improve the clarity of the images formed by the telescope.

    The project will deliver a faster, more flexible real-time controller (RTC), as well as a better, lower noise camera for wavefront sensing. This will reduce the camera readout and computation time between the time that an image is captured and a correction for atmospheric blurring is made.

    4

    “Any delay means the correction is applied for atmospheric turbulence that has already started to change. Even if the correction happens in just a few milliseconds, we want to reduce the delay to a minimum. The new RTC computer and camera uses advanced technology to do just that,” said Sylvain Cetre, a software engineer at Keck Observatory who plays a lead role in developing the new RTC.

    Recognizing this as a valuable STEM (Science, Technology, Engineering, and Mathematics) opportunity for education and workforce development, Keck Observatory will include a postdoc as well as a Hawaii college student from the summer Akamai Internship Program to work on the development of the project.

    “Part of Keck Observatory’s mission is to train and prepare future generations so the work continues long after we are gone,” said Jason Chin, a senior engineer at Keck Observatory and project manager for the new RTC. “Many of Hawaii’s finest students, scientists, and engineers end up working on the mainland away from their families. We want to show them there is a vibrant tech industry in Hawaii. One of the ways we do that is by participating in the Akamai Internship Program, which has one of the highest retention rates for Hawaii college students staying in the STEM field. We are proud that many are working in our local tech industry.”

    Co-Principal Investigators Andrea Ghez, Director of the UCLA Galactic Center Group, Jessica Lu, Assistant Astronomy Professor at UC Berkeley, Dimitri Mawet, Associate Astronomy Professor at Caltech, and Tommaso Treu, Physics and Astronomy Professor at UCLA, will also involve graduate and postdoc students. Their teams will use the new capabilities of Keck Observatory’s AO system to pursue science projects in three fields of study:

    1.Characterizing planets around low mass stars via direct imaging and spectroscopy

    2.Testing Einstein’s Theory of General Relativity and understanding supermassive black hole interactions at the Galactic Center

    3.Constraining Dark Matter, the Hubble constant, and Dark Energy via strong gravitational lensing

    “These instrumentation improvements will not only enhance the scientific return of our existing AO system, but it will also provide an excellent platform for future improvements,” said Wizinowich. “We were very pleased to learn that our proposal was successful.”

    The upgrade is expected to be completed by the end of 2020.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.


    Keck UCal

     
  • richardmitnick 7:22 am on May 27, 2017 Permalink | Reply
    Tags: Adaptive Optics, , Fifth force, , , ,   

    From KECK: “New Method of Searching for Fifth Force” 

    Keck Observatory

    Keck Observatory.
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    1
    The orbits of two stars, S0-2 and S0-38 located near the Milky Way’s supermassive black hole will be used to test Einstein’s theory of General Relativity and potentially generate new gravitational models. IMAGE CREDIT: S. SAKAI/A.GHEZ/W. M. KECK OBSERVATORY/ UCLA GALACTIC CENTER GROUP

    W. M. Keck Observatory Data Leads To First Of Its Kind Test of Einstein’s Theory of General Relativity.

    May 26, 2017
    No writer credit found.

    A UCLA-led team has discovered a new way of probing the hypothetical fifth force of nature using two decades of observations at W. M. Keck Observatory, the world’s most scientifically productive ground-based telescope.

    There are four known forces in the universe: electromagnetic force, strong nuclear force, weak nuclear force, and gravitational force. Physicists know how to make the first three work together, but gravity is the odd one out. For decades, there have been theories that a fifth force ties gravity to the others, but no one has been able to prove it thus far.

    “This is really exciting. It’s taken us 20 years to get here, but now our work on studying stars at the center of our galaxy is opening up a new method of looking at how gravity works,” said Andrea Ghez, Director of the UCLA Galactic Center Group and co-author of the study.

    The research is published in the current issue of Physical Review Letters.

    Ghez and her co-workers analyzed extremely sharp images of the center of our galaxy taken with Keck Observatory’s adaptive optics (AO). Ghez used this cutting-edge system to track the orbits of stars near the supermassive black hole located at the center of the Milky Way.

    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    Their stellar path, driven by gravity created from the supermassive black hole, could give clues to the fifth force.

    “By watching the stars move over 20 years using very precise measurements taken from Keck Observatory data, you can see and put constraints on how gravity works. If gravitation is driven by something other than Einstein’s theory of General Relativity, you’ll see small variations in the orbital paths of the stars,” said Ghez.

    2
    Pictured above: UCLA Professor of Astrophysics and Galactic Center Group Director Andrea Ghez, a Keck Observatory astronomer and recipient of the 2015 Bakerian Medal. IMAGE CREDIT: KYLE ALEXANDER

    This is the first time the fifth force theory has been tested in a strong gravitational field such as the one created by the supermassive black hole at the center of the Milky Way. Historically, measurements of our solar system’s gravity created by our sun have been used to try and detect the fifth force, but that has proven difficult because its gravitational field is relatively weak.

    “It’s exciting that we can do this because we can ask a very fundamental question – how does gravity work?” said Ghez. “Einstein’s theory describes it beautifully well, but there’s lots of evidence showing the theory has holes. The mere existence of supermassive black holes tells us that our current theories of how the universe works are inadequate to explain what a black hole is.”

    Ghez and her team, including lead author Aurelien Hees and co-author Tuan Do, both of UCLA, are looking forward to summer of 2018. That is when the star S0-2 will be at its closest distance to our galaxy’s supermassive black hole. This will allow the team to witness the star being pulled at maximum gravitational strength – a point where any deviations to Einstein’s theory is expected to be the greatest.

    About Adaptive Optics

    W. M. Keck Observatory is a distinguished leader in the field of adaptive optics (AO), a breakthrough technology that removes the distortions caused by the turbulence in the Earth’s atmosphere.

    Keck Observatory pioneered the astronomical use of both natural guide star (NGS) and laser guide star adaptive optics (LGS AO) and our current systems now deliver images three to four times sharper than the Hubble Space Telescope. AO has imaged the four massive planets orbiting the star HR8799, measured the mass of the giant black hole at the center of our Milky Way Galaxy, discovered new supernovae in distant galaxies, and identified the specific stars that were their progenitors.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

     
  • richardmitnick 8:58 am on May 25, 2017 Permalink | Reply
    Tags: Adaptive Optics, , , , , ,   

    From Nautilus: “Opening a New Window into the Universe” 

    Nautilus

    Nautilus

    April 2017
    Andrea Ghez, UCLA, UCO

    7
    Andrea Ghez. PBS NOVA

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California

    Keck Observatory, Mauna Kea, Hawaii, USA

    New technology could bring new insights into the nature of black holes, dark matter, and extrasolar planets.

    Earthbound telescopes see stars and other astronomical objects through a haze. The light waves they gather have traveled unimpeded through space for billions of years, only to be distorted in the last millisecond by the Earth’s turbulent atmosphere. That distortion is now even more important, because scientists are preparing to build the three largest telescopes on Earth, each with light-gathering surfaces of 20 to 40 meters across.

    The new giant telescopes:

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile


    TMT-Thirty Meter Telescope, proposed for Mauna Kea, Hawaii, USA


    Giant Magellan Telescope, to be at Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile

    In principle, the larger the telescope, the higher the resolution of astronomical images. In practice, the distorting veil of the atmosphere has always limited what can be achieved. Now, a rapidly evolving technology known as adaptive optics can strip away the veil and enable astronomers to take full advantage of current and future large telescopes. Indeed, adaptive optics is already making possible important discoveries and observations, including: the discovery of the supermassive black hole at the center of our galaxy, proving that such exotic objects exist; the first images and spectra of planetary systems around other stars; and high-resolution observations of galaxies forming in the early universe.

    But adaptive optics has still not delivered its full scientific potential.

    ESO 4LGSF Adaptive Optics Facility (AOF)

    Existing technology can only partially correct the atmospheric blurring and cannot provide any correction for large portions of the sky or for the majority of the objects astronomers want to study.

    The project we propose here to fully exploit the potential of adaptive optics by taking the technology to the next level would boost research on a number of critical astrophysical questions, including:

    What are supermassive black holes and how do they work? Adaptive Optics has opened a new approach to studying supermassive black holes—through stellar orbits—but only the brightest stars, the tip of the iceberg, have been measured. With next generation adaptive optics we will be able to take the next leap forward in our studies of these poorly understood objects that are believed to play a central role in our universe. The space near the massive black hole at the center of our galaxy, for example, is a place where gravitational forces reach extreme levels. Does Einstein’s general theory of relativity still apply, or do exotic new physical phenomena emerge? How do these massive black holes shape their host galaxies? Early adaptive optics observations at the galactic center have revealed a completely unexpected environment, challenging our notions on the relationship between black holes and galaxies, which are a fundamental ingredient to cosmological models. One way to answer both of these questions is to find and measure the orbits of faint stars that are closer to the black hole than any known so far—which advanced adaptive optics would make possible.
    The first direct images of an extrasolar planet—obtained with adaptive optics—has raised fundamental questions about star and planet formation. How exactly do new stars form and then spawn planets from the gaseous disks around them? New, higher resolution images of this process—with undistorted data from larger telescopes—can help answer this question, and may also reveal how our solar system was formed. In addition, although only a handful of new-born planets has been found to date, advanced adaptive optics will enable astronomers to find many more and help determine their composition and life-bearing potential.
    Dark matter and dark energy are still completely mysterious, even though they constitute most of the universe.


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam

    But detailed observations using adaptive optics of how light from distant galaxies is refracted around a closer galaxy to form multiple images—so-called gravitational lensing—can help scientists understand how dark matter and dark energy change space itself.

    In addition, it is clear that telescopes endowed with advanced adaptive optics technology will inspire a whole generation of astronomers to design and carry out a multitude of innovative research projects that were previously not possible.

    4
    The laser system used to make artificial guide stars that sense the blurring effects of the Earth’s atmosphere being used on both Keck I and Keck II during adaptive optics observations of the center of our Galaxy. Next Generation Adaptive Optics would have multiple laser beams for each telescope. Ethan Tweedie

    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    The technology of adaptive optics is quite simple, in principle. First, astronomers measure the instantaneous turbulence in the atmosphere by looking at the light from a bright, known object—a “guide star”—or by using a laser tuned to make sodium atoms in a thin layer of the upper atmosphere fluoresce and glow as an artificial guide star.

    6
    ESO VLT Adaptive Optics new Guide Star laser light

    The turbulence measurements are used to compute (also instantaneously) the distortions that turbulence creates in the incoming light waves. Those distortions are then counteracted by rapidly morphing the surface of a deformable mirror in the telescope. Measurements and corrections are done hundreds of times per second—which is only possible with powerful computing capability, sophisticated opto-mechanical linkages, and a real-time control system. We know how to build these tools.

    Of course, telescopes that operate above the atmosphere, such as the Hubble Space Telescope, don’t need adaptive optics.

    NASA/ESA Hubble Telescope

    But both the Hubble and the coming next generation of space telescopes are small compared to the enormous earth-based telescopes now being planned.


    LSST Camera, built at SLAC



    LSST telescope, currently under construction at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    And for the kinds of research that require very high resolution, such as the topics mentioned above and many others, there is really no substitute for the light-gathering power of telescopes too huge to be put into space.

    The next generation of adaptive optics could effectively take even the largest earth-bound telescopes “above the atmosphere” and make them truly amazing new windows on the universe. We know how to create this capability—the technology is in hand and the teams are assembled. It is time to put advanced adaptive optics to work.

    Creating Next Generation Adaptive Optics

    Adaptive optics (AO) imaging technology is used to improve the performance of optical systems by correcting distortions on light waves that have traveled through a turbulent medium. The technology has revolutionized fields from ophthalmology and vision science to laser communications. In astronomy, AO uses sophisticated, deformable mirrors controlled by fast computers to correct, in real-time, the distortion caused by the turbulence of the Earth’s atmosphere. Telescopes equipped with AO are already producing sharper, clearer views of distant astronomical objects than had ever before been possible, even from space. But current AO systems only partially correct for the effects of atmospheric blurring, and only when telescopes are pointed in certain directions. The aim of Next Generation Adaptive Optics is to overcome these limitations and provide precise correction for atmospheric blurring anywhere in the sky.

    One current limitation is the laser guide star that energizes sodium atoms in the upper atmosphere and causes them to glow as an artificial star used to measure the atmospheric distortions. This guide “star” is relatively close, only about 90 kilometers above the Earth’s surface, so the technique only probes a conical volume of the atmosphere above the telescope, and not the full cylinder of air through which genuine star light must pass to reach the telescope. Consequently, much of the distorting atmospheric structure is not measured. The next generation AO we propose will employ seven laser guide stars, providing full coverage of the entire cylindrical path travelled by light from the astronomical object being studied.

    6
    The next generation of adaptive optics will have several laser-created artificial guide stars, better optics, higher performance computers, and more advanced science instruments. Such a system will deliver the highest-definition images and spectra over nearly the entire sky and will enable unique new means of measuring the properties of stars, planets, galaxies, and black holes.
    J.Lu (U of Hawaii) & T. Do (UCLA)

    This technique can map the 3-D structure of the atmosphere, similar to how MRI medical imaging maps the human body. Simulations demonstrate that the resulting corrections will be excellent and stable, yielding revolutionary improvements in imaging. For example, the light from a star will be concentrated into a tiny area of the focal plane camera, and be far less spread out than it is with current systems, giving sharp, crisp images that show the finest detail possible.

    This will be particularly important for existing large telescopes such as the W. M. Keck Observatory (WMKO) [above]—currently the world’s leading AO platform in astronomy. Both our team—the UCLA Galactic Center Group (GCG)—and the WMKO staff have been deeply involved in the development of next generation AO systems.

    The quantum leap in the quality of both imaging and spectroscopy that next generation AO can bring to the Keck telescopes will likely pave the way for advanced AO systems on telescopes around the globe. For the next generation of extremely large telescopes, however, these AO advances will be critical. This is because the cylindrical volume of atmosphere through which light must pass to reach the mirrors in such large telescopes is so broad that present AO techniques will not be able to provide satisfactory corrections. For that reason, next generation AO techniques are critical to the future of infrared astronomy, and eventually of optical astronomy as well.

    The total proposed budget is $80 million over five years. The three major components necessary to take the leap in science capability include the laser guide star system, the adaptive optics system, and a powerful new science instrument, consisting of an infrared imager and an infrared spectrograph, that provides the observing capability to take advantage of the new adaptive optics system. This investment in adaptive optics will also help develop a strong workforce for other critical science and technology industries, as many students are actively recruited into industry positions in laser communications, bio-medical optics, big-data analytics for finance and business, image sensing and optics for government and defense applications, and the space industry. This investment will also help keep the U.S. in the scientific and technological lead. Well-funded European groups have recognized the power of AO and are developing competitive systems, though the next generation AO project described here will set an altogether new standard.

    Federal funding agencies find the science case for this work compelling, but they have made clear that it is beyond present budgetary means. Therefore, this is an extraordinary opportunity for private philanthropy—for visionaries outside the government to help bring this ambitious breakthrough project to reality and open a new window into the universe.

    Andrea Ghez is the Lauren B. Leichtman & Arthur E. Levine Chair in Astrophysics Director, UCLA Galactic Center Group.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 4:31 am on April 27, 2016 Permalink | Reply
    Tags: Adaptive Optics, , , ,   

    From ESO: “Four Lasers Over Paranal” 

    ESO 50 Large

    European Southern Observatory

    27 April 2016
    Domenico Bonaccini Calia
    ESO
    Garching bei München, Germany
    Tel: +49 89 3200 6567
    Cell: +49 (0) 174 5246 013
    Email: Domenico.Bonaccini@eso.org

    Wolfgang Hackenberg
    ESO
    Garching bei München, Germany
    Tel: +49 89 3200 6782
    Email: whackenb@eso.org

    Richard Hook
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    1

    On 26 April 2016 ESO’s Paranal Observatory in Chile hosted an event to mark the first light for the four powerful lasers that form a crucial part of the adaptive optics systems on ESO’s Very Large Telescope. Attendees were treated to a spectacular display of cutting-edge laser technology against the majestic skies of Paranal. These are the most powerful laser guide stars ever used for astronomy and the event marks the first use of multiple laser guide stars at ESO.

    2
    Schematic view of the Four Laser Guide Star Facility on the ESO VLT

    3
    The most powerful laser guide star system in the world sees first light at the Paranal Observatory

    ESO staff were present for the event, along with senior representatives of the companies that have manufactured the different components of the new system.

    The Four Laser Guide Star Facility (4LGSF) shines four 22-watt laser beams into the sky to create artificial guide stars by making sodium atoms in the upper atmosphere glow so that they look just like real stars [1]. The artificial stars allow the adaptive optics systems to compensate for the blurring caused by the Earth’s atmosphere and so that the telescope can create sharp images. Using more than one laser allows the turbulence in the atmosphere to be mapped in far greater detail to significantly improve the image quality over a larger field of view.

    The Four Laser Guide Star Facility is an example of how ESO enables European industry to lead complex research and development projects. The fibre laser used by the 4LGSF is also one of the most successful transfers of ESO technology to industry.

    TOPTICA, the German main contractor, was responsible for the laser system and provided the oscillator, the frequency doubler, and the system control software. Wilhelm Kaenders, president of TOPTICA, said: “TOPTICA has enjoyed the collaboration with ESO tremendously. It is not only the personal thrill of being engaged with astronomy, an old passion, again, and working with very clever ESO technologists; it is also the inspiration that we have received for our own commercial product development.” [2]

    MPBC of Canada provided the fibre laser pumps and Raman amplifiers, which are based on an ESO licensed patent. Jane Bachynski, President of MPB Communications Inc. said: “MPBC is proud to have worked with ESO in the development of Raman fibre amplifiers to much higher powers, allowing MPBC to bring this technology to the stars. This event marks the culmination of many years of hard work on behalf of all involved.” [3]

    TNO in the Netherlands manufactured the optical tube assemblies, which expand the laser beams and direct them into the sky. Paul de Krom, CEO of TNO, said: “TNO valued the cooperative working environment during the development of the optical tube assemblies and looks forward to the opportunity to work with ESO and the other partners in the 4LGSF project in the future.” [4]

    The 4LGSF is part of the Adaptive Optics Facility on Unit Telescope 4 of the VLT, designed specifically to provide the adaptive optics systems GALACSI/MUSE and GRAAL/HAWK-I with four sodium laser guide stars. With this new facility, Paranal Observatory continues to have the most advanced and the largest number of adaptive optics systems in operation today.

    The 4LGSF lasers were developed by ESO with industry and have already been procured, among others, by the Keck Observatory (which contributed to the industrial laser development cost along with the European Commission) and the Subaru Telescope. In the future these industrial lasers will also feature on the telescopes at the Gemini Observatory and will be the preferred choice for several other observatories and extremely large telescope projects.

    The new techniques developed for the Four Laser Guide Star Facility pave the way for the adaptive optics system of the European Extremely Large Telescope (E-ELT), the world’s biggest eye on the sky.
    Notes

    [1] The 4LGSF is the second generation laser guide star facility, built by ESO for the Adaptive Optics Facility on the UT4 VLT telescope. The two critical long-lead items for the 4LGSF, the laser system and the optical tube assemblies for the laser launch telescope systems have been procured from industry. The fibre Raman laser technology, on which the 4LGSF laser system is based, has been developed at ESO, patented and licensed to industry.

    [2] This project has allowed TOPTICA to extend its products into a new wavelength and output power regime. It now produces the SodiumStar 20/2, which is recognised as a quasi-standard for existing and planned telescopes around the world. All next generation extremely large telescope projects, for example, use the SodiumStar laser as their baseline. During the seven years of collaboration with ESO the company has grown from 80 people to more than 200 today.

    [3] MPBC’s collaboration with ESO has also generated an additional benefit, in the form of an offshoot product line of single frequency amplification products at virtually any wavelength, supporting novel applications for the scientific and commercial research community.

    [4] The developments by TNO also involved contributions from many suppliers from the Netherlands (Vernooy, Vacutech, Rovasta, Schott Benelux, Maxon Motor Benelux, IPS technology, Sensordata and WestEnd) and other international companies (RMI, Qioptiq, Laser Components, Carl Zeiss, GLP, Faes, Farnell, Eriks and Pfeiffer). The knowledge and technologies advanced by working with ESO feed into TNO’s Dutch and European partners, in fields including astronomy, communications, semiconductor manufacturing, medical devices, space science and Earth observation.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition
    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

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

    ESO LaSilla
    LaSilla

    ESO VLT
    VLT

    ESO Vista Telescope
    VISTA

    ESO NTT
    NTT

    ESO VLT Survey telescope
    VLT Survey Telescope

    ALMA Array
    ALMA

    ESO E-ELT
    E-ELT

    ESO APEX
    Atacama Pathfinder Experiment (APEX) Telescope

     
  • richardmitnick 3:01 pm on December 8, 2015 Permalink | Reply
    Tags: Adaptive Optics, , ,   

    From Keck: “$4 Million Laser Marks Ground Zero for Adaptive Optics Science” 

    Keck Observatory

    Keck Observatory
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    December 8, 2015
    MEDIA
    Steve Jefferson
    Communication Officer
    W. M. Keck Observatory
    sjefferson@keck.hawaii.edu

    1
    Image from the launching point of the telescope looking up into the night sky. The central hole in the beam is due to the secondary mirror obscuration on the laser beam launch telescope and is used to align the laser beam. Credit: W. M. Keck Observatory

    2
    The top spot is the artificially created laser guide star in the mesosphere with sodium atoms excited by the laser. The star pattern and surrounding lopes, seen by the acquisition camera, show the structures of the telescope and the equipment in the light path. The bottom spot is a reflection of the laser star on the camera optics. Credit: W. M. Keck Observatory

    3
    A point spread image shows the symmetry of the artificially created guide star in the mesosphere.

    Hawaii’s W. M. Keck Observatory has successfully deployed a $4 million laser system that provides a marked increase in the resolution and clarity of what are already the most scientifically productive telescopes on Earth. The new laser was projected on the sky for the first time on the evening of December 1, 2015 and will allow scientists from around the world to observe the heavens above Maunakea in unprecedented detail.

    “The Next Generation Laser System is the third generation of lasers at Keck Observatory, which has been pioneering Laser Guide Star Adaptive Optics on big telescopes since 2001,” said Jason Chin, the project manager for the new laser at Keck Observatory.

    The first Laser Guide Star Adaptive Optics system on a large telescope was commissioned on the Keck II telescope in 2004 and, among many other firsts, helped reveal the black hole at the center of the Milky Way – one the most significant astronomical discoveries. The second laser system was installed in 2011 on the Keck I telescope, propelling Keck Observatory’s lead as the premiere Adaptive Optics research facility in the world. To date more than 240 science results from these laser systems have been published in astronomical journals.

    Keck Observatory’s Laser Guide Star systems create an artificial star in the earth’s mesosphere, at an altitude of roughly 60 miles, by energizing a naturally occurring layer of sodium atoms, causing them to fluoresce. The adaptive optics system uses this artificial laser guide star to measure the aberrations introduced by turbulence in the earth’s atmosphere. A six-inch diameter deformable mirror with 349 actuators is then used to correct for these aberrations at a rate of 1,000 times per second, effectively taking the twinkle out of the stars and providing near-perfect detail for planets, stars and galaxies. Combined with the 10-meter diameter primary mirror, Keck Observatory can offer images with five times the resolution of even the Hubble Space Telescope.

    The new laser is the result of a collaboration between Keck Observatory and the European Southern Observatory to develop a more efficient and powerful facility class, commercial laser for astronomy. The new laser, fabricated by TOPTICA in Germany and MPBC in Canada meets both goals handily: the power consumption on the new system is down to 1.2 kW from the previous 80 kW used by the former dye laser system while performance has increased by a factor of ten. Further, the new laser can transition from off to an operational state in five minutes – a dramatic improvement over the five to six hours for the dye laser, which was decommissioned in October to make room for the new laser.

    Perhaps most significantly, this is first of the new generation of lasers that all future telescopes are planning on and are looking to Hawaii’s findings to build their systems.

    Funding for the project came from the Gordon and Betty Moore Foundation, the W. M. Keck Foundation and Friends of Keck Observatory. Initial seed funding was provided by the National Science Foundation.

    More than one-third of the budget was spent in Hawaii designing and installing the systems and related infrastructure to support and operate the new laser. The remaining budget was spent on the laser itself – more than $2.5 million. The project also provided infrastructure for adding two additional lasers to support laser tomography in order to determine the distribution of atmospheric turbulence versus altitude. Once funded, the additional lasers can be easily added to the system and would allow a much larger area of the sky to be sampled with even better correction of the atmospheric turbulence.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes near the summit of Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrographs and world-leading laser guide star adaptive optics systems.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

    Keck NASA

    Keck Caltech

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: