Tagged: Keck Observatory Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 7:27 pm on March 19, 2015 Permalink | Reply
    Tags: , , , Keck Observatory   

    From Keck: “Unusual Asteroid Suspected of Spinning to Explosion” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    March 19, 2015
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    1
    Credit: M. Drahus, W. Waniak (OAUJ) / W. M. Keck Observatory
    Active asteroid P/2012 F5 captured by Keck II/DEIMOS in mid-2014. Top panel shows a wide-angle view of the main nucleus and smaller fragments embedded in a long dust trail. Bottom panel shows a close-up view with the trail numerically removed to enhance the visibility of the fragments.

    A team led by astronomers from the Jagiellonian University in Krakow, Poland, recently used the W. M. Keck Observatory in Hawaii to observe and measure a rare class of “active asteroids” that spontaneously emit dust and have been confounding scientists for years. The team was able to measure the rotational speed of one of these objects, suggesting the asteroid spun so fast it burst, ejecting dust and newly discovered fragments in a trail behind it. The findings are being published in Astrophysical Journal Letters on March 20, 2015.

    2
    Credit: M. Drahus, W. Waniak (OAUJ) / W. M. Keck Observatory
    Brightness fluctuations of the nucleus of P/2012 F5 during two consecutive rotation cycles. Presented versus time (top panel) and versus the nucleus rotation phase (bottom panel).

    Unlike the hundreds of thousands of asteroids in the main belt of our solar system, which move cleanly along their orbits, active asteroids were discovered several years ago mimicking comets with their tails formed by calm, long lasting ice sublimation.

    Then in 2010 a new type of active asteroid was discovered, which ejected dust like a shot without an obvious reason. Scientists gravitated around two possible hypotheses. One states the explosion is a result of a hypervelocity collision with another minor object. The second popular explanation describes it as a consequence of “rotational disruption”, a process of launching dust and fragments by spinning so fast, the large centrifugal forces produced exceed the object’s own gravity, causing it to break apart. Rotational disruption is the expected final state of what is called the YORP effect – a slow evolution of the rotation rate due to asymmetric emission of heat.

    To date, astronomers have identified four objects suspected of either collision- or rotation-driven activity. These four freakish asteroids are all very small, at a kilometer or less, which makes them unimaginably faint when viewed from a typical distance of a couple hundred million miles. Despite prior attempts, the tiny size of the objects kept scientists from determining some of the key characteristics that could prove or disprove the theories.

    Until last August, when the team led by Michal Drahus of the Jagiellonian University was awarded time at Keck Observatory.

    “When we pointed Keck II at P/2012 F5 last August, we hoped to measure how fast it rotated and check whether it had sizable fragments. And the data showed us all that,” Drahus said.

    The team discovered at least four fragments of the object, previously established to have impulsively ejected dust in mid-2011. They also measured a very short rotation period of 3.24 hours – fast enough to cause the object impulsively explode.

    “This is really cool because fast rotation has been suspected of catapulting dust and triggering fragmentation of some active asteroids and comets. But up until now we couldn’t fully test this hypothesis as we didn’t know how fast fragmented objects rotate,” Drahus said.

    The astronomers calculated the object’s rotation period by measuring small periodic fluctuations in brightness. Such oscillations occur naturally as the irregular nucleus rotates about its spin axis and reflects different amounts of sunlight during a rotation cycle.

    “This is a well-established technique but its application on faint targets is challenging,” said Waclaw Waniak of the Jagiellonian University who processed the Keck Observatory data. “The main difficulty is the brightness must to be probed every few minutes so we don’t have time for long exposures. We needed the huge collecting area of Keck II, which captures a plentiful amount of photons in a very short time.”

    The photons were then concentrated in the telescope’s light path and sent to the DEIMOS instrument to produce the data that allowed the scientists to determine P/2012 F5’s nature. While monitoring brightness in the individual 3-minute exposures, scientists also compiled all the data to produce a single ultra-deep image, which revealed the fragments.

    The success wouldn’t be possible if the selected target, P/2012 F5, were not an ideal candidate for this study. Alex R. Gibbs discovered the object on March 22, 2012 with the Mount Lemmon 1.5 meter reflector. It was initially classified as a comet, based solely on its “dusty” look. But two independent teams quickly have shown all this dust was emitted in a single pulse about a year before the discovery – something that doesn’t happen to comets. When the dust settled in 2013, another team using the University of Hawaii’s 2.2-meter telescope on Mauna Kea detected a star-like nucleus and suggested a maximum size of 2 kilometers.

    “We suspected that this upper limit was close to the actual size of the object. Consequently, we chose to observe P/2012 F5 because – despite its small size – it appeared to be the largest and easiest to observe active asteroid suspected of rotational disruption,” said Jessica Agarwal of the Max Planck Institute for Solar System Research who chose P/2012 F5 as the subject.

    As a result of the study, P/2012 F5 is the first freshly fragmented object in the solar system with a well-determined spin rate, and this spin rate turns out to be the fastest among the active asteroids. A careful analysis made by the team shows that these two features of the object are consistent with the “rotational disruption” scenario. But alternative explanations, such as fragmentation due to an impact, cannot be completely ruled out.

    “There are many faster rotators among asteroids which don’t show signs of a recent mass loss. And there are many hypervelocity impactors straying out there and looking for targets to hit – be it a fast or slow rotator,” Drahus said.

    “We’re indebted to the Caltech Optical Observatories for generously awarding Keck Observatory time for this program,” said Drahus – formerly a NRAO Jansky Fellow at Caltech. “Without the huge collecting area of Keck II’s 10-meter mirror, we wouldn’t be able to achieve our goals so swiftly.”

    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

     
  • richardmitnick 3:36 pm on March 5, 2015 Permalink | Reply
    Tags: , , Keck Observatory   

    From Keck: “Thermonuclear Supernova Ejects Galaxy’s Fastest Star” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    March 5, 2015
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    1
    An artist impression of the mass-transfer phase followed by a double-detonation supernova that leads to the ejection of US 708. While this illustration shows the supernova (bottom center) and the ejected star (left) at the same time, in reality the supernova would have been faded away long before the star reached that position.

    Scientists using the W. M. Keck Observatory and Pan-STARRS1 telescopes on Hawaii have discovered a star that breaks the galactic speed record, traveling with a velocity of about 1,200 kilometers per second or 2.7 million miles per hour. This velocity is so high, the star will escape the gravity of our galaxy. In contrast to the other known unbound stars, the team showed that this compact star was ejected from an extremely tight binary by a thermonuclear supernova explosion. These results will be published in the March 6 issue of Science.

    Pann-STARSR1 Telescope
    Pann-STARRS1 interior
    Pan-STARRS1

    Stars like the Sun are bound to our Galaxy and orbit its center with moderate velocities. Only a few so-called hypervelocity stars are known to travel with velocities so high that they are unbound, meaning they will not orbit the galaxy, but instead will escape its gravity to wander intergalactic space.

    A close encounter with the supermassive black hole at the centre of the Milky Way is typically presumed the most plausible mechanism for kicking these stars out of the galaxy.

    A team of astronomers led by Stephan Geier (European Southern Observatory, Garching) observed the known high-velocity star know as US 708 with the Echellette Spectrograph and Imager instrument on the 10-meter, Keck II telescope to measure its distance and velocity along our line of sight.

    Keck Eschellette Spectrograph
    Echellette Spectrograph and Imager instrument

    By carefully combining position measurements from digital archives with newer positions measured from images taken during the course of the Pan-STARRS1 survey, they were able to derive the tangential component of the star’s velocity (across our line of sight).

    Putting the measurements together, the team determined the star is moving at about 1,200 kilometers per second – much higher than the velocities of previously known stars in the Milky Way galaxy. More importantly, the trajectory of US 708 means the supermassive black hole at the galactic center could not be the source of US 708’s extreme velocity.

    US 708 has another peculiar property in marked contrast to other hypervelocity stars: it is a rapidly rotating, compact helium star likely formed by interaction with a close companion. Thus, US 708 could have originally resided in an ultra compact binary system, transferring helium to a massive white dwarf companion, ultimately triggering a thermonuclear explosion of a type Ia supernova. In this scenario, the surviving companion, i.e. US 708, was violently ejected from the disrupted binary as a result, and is now travelling with extreme velocity.

    These results provide observational evidence of a link between helium stars and thermonuclear supernovae, and is a step towards understanding the progenitor systems of these mysterious explosions.

    ESI (Echellette Spectrograph and Imager) is a medium-resolution visible-light spectrograph that records spectra from 0.39 to 1.1 microns in each exposure. Built at UCO/Lick Observatory by a team led by Prof. Joe Miller, ESI also has a low-resolution mode and can image in a 2 x 8 arcmin field of view. An upgrade provided an integral field unit that can provide spectra everywhere across a small, 5.7 x 4.0 arcsec field. Astronomers have found a number of uses for ESI, from observing the cosmological effects of weak gravitational lensing to searching for the most metal-poor stars in our galaxy.

    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

     
  • richardmitnick 8:19 pm on January 16, 2015 Permalink | Reply
    Tags: , , Keck Observatory   

    From Keck: “Three Almost Earth-Size Planets Found Orbiting Nearby Star” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    January 16, 2015
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    Last week, a team of scientists discovered a system of three planets, each just larger than Earth, orbiting a nearby star called EPIC 201367065. The three planets are 1.5-2 times the size of Earth. The outermost planet orbits on the edge of the so-called “habitable zone,” where the temperature may be just right for liquid water, believed necessary to support life, on the planet’s surface. The paper, A Nearby M Star with Three Transiting Super-Earths Discovered by K2, was submitted to the Astrophysical Journal today and is available here.

    “The compositions of these newfound planets are unknown, but, there is a very real possibility the outer planet is rocky like Earth,” said Erik Petigura, a University of California, Berkeley graduate student who spent a year visiting the UH Institute for Astronomy. “If so, this planet could have the right temperature to support liquid water oceans.”

    The planets were confirmed by the NASA Infrared Telescope Facility (IRTF) the W. M. Keck Observatory in Hawaii as well as telescopes in California and Chile.

    NASA Infrared Telescope facility
    NASA IRTF

    “Keck’s contribution to this discovery was vital,” said Andrew Howard, a University of Hawaii astronomer on the team. “The adaptive optics image from NIRC2 showed the star hosting these three planets is a single star, not a binary. It showed that the planets are real and not an artifact of some masquerading multi-star system.”

    Keck NIRC2
    NIRC2

    Due to the competitive state of planet finding, and the fact that time on the twin Keck telescopes are scheduled months in advance, the team asked UC Berkeley Astronomer, Imke de Pater to gather some data during her scheduled run.

    “The collegiality of the Keck Observatory community is just wonderful,” Howard said. “Imke took time away from her own science observations to get us images of this system, all on a couple hours’ notice.”

    The new discovery paves the way for studies of the atmosphere of a warm planet nearly the size of Earth.

    “We’ve learned in the past year that planets the size and temperature of Earth are common in our Milky Way galaxy,” Howard said. “We also discovered some Earth-size planets that appear to be made of the same materials as our Earth, mostly rock and iron.”

    The astronomers next hope to determine what elements are in the planets’ atmospheres. If these warm, nearly Earth-size planets have thick, hydrogen-rich atmospheres, there is not much chance for life.

    “A thin atmosphere made of nitrogen and oxygen has allowed life to thrive on Earth. But nature is full of surprises. Many extrasolar planets discovered by the Kepler Mission are enveloped by thick, hydrogen-rich atmospheres that are probably incompatible with life as we know it,” said Ian Crossfield, the University of Arizona astronomer who led the study.

    NASA Kepler Telescope
    Kepler

    The discovery is all the more remarkable because Kepler is now hobbled by the loss of two reaction wheels that kept it pointing at a fixed spot in space. Kepler, launched in 2009, was reborn in 2014 as “K2” with a clever strategy of pointing the telescope in the plane of the Earth’s orbit to stabilize the spacecraft. Kepler is back to mining the cosmos for planets by searching for eclipses, or transits, as planets orbit in front of their host stars and periodically block some of the starlight.

    “I was devastated when Kepler was crippled by a hardware failure,” Petigura added. “It’s a testament to the ingenuity of NASA engineers and scientists that Kepler can still do great science.”

    Kepler sees only a small fraction of the planetary systems in its gaze, those with orbital planes aligned edge-on to our view from Earth. Planets with large orbital tilts are simply missed by Kepler.

    “It’s remarkable that the Kepler telescope is now pointed in the ecliptic, the plane that Earth sweeps out as it orbits the Sun,” Fulton explains. “This means that some of the planets discovered by K2 will have orbits lined up with Earth’s, a celestial coincidence that allows Kepler to see the alien planets, and Kepler-like telescopes in those very planetary systems (if there are any) to discover Earth.”

    “Here’s looking at you, looking at me,” said Howard.

    In addition to Howard and Petigura, UH graduate students Benjamin Fulton and Kimberly Aller, and UH astronomer Michael Liu were among the two dozen scientists who contributed to the study.

    NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    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

     
  • richardmitnick 9:37 pm on January 8, 2015 Permalink | Reply
    Tags: , , Keck Observatory   

    From Keck: “Comprehensive Andromeda Study Hints of Violent History” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    January 8, 2015
    Media Contact:

    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    Science Contacts:

    Claire Dorman
    UC Santa Cruz
    cdorman@ucolick.org

    Puragra (Raja) Guhathakurta
    (408) 455-3036
    UC Santa Cruz
    raja@ucolick.org

    A detailed study of the motions of different stellar populations in Andromeda galaxy by UC Santa Cruz scientists using W. M. Keck Observatory data has found striking differences from our own Milky Way, suggesting a more violent history of mergers with smaller galaxies in Andromeda’s recent past. The findings are being presented on Thursday, January 8, at the winter meeting of the American Astronomical Society in Seattle.

    a
    The Andromeda Galaxy
    Adam Evans

    The structure and internal motions of the stellar disk of a spiral galaxy hold important keys to understanding the galaxy’s formation history. The Andromeda galaxy, also called M31, is the closest spiral galaxy to the Milky Way and the largest in the local group of galaxies.

    “In the Andromeda galaxy we have the unique combination of a global yet detailed view of a galaxy similar to our own. We have lots of detail in our own Milky Way, but not the global, external perspective,” said Puragra Guhathakurta, professor of astronomy and astrophysics at the University of California, Santa Cruz.

    The new study, led by UC Santa Cruz graduate student Claire Dorman and Guhathakurta, combined data from two large surveys of stars in Andromeda conducted at the Keck Observatory in Hawaii as well as data from the Hubble Space Telescope.

    NASA Hubble Telescope
    Hubble

    The Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo (SPLASH) survey used data from the 10-meter Keck II telescope, fitted with the DEIMOS multi-object spectrograph to measure radial velocities of more than 10,000 individual bright stars in Andromeda.

    Keck DEIMOS
    DEIMOS

    “The sheer light-gathering power of the Keck Observatory, the superb quality of DEIMOS spectra, free of instrumental/atmospheric artifacts, and its ability to obtain spectra of as many as 300 stars at once were crucial to the success of this experiment,” said Guhathakurta. “The Andromeda galaxy is about 2.5 million light years away so even its most luminous stars generally appear quite faint from our vantage point. To measure precise stellar velocities, the white light of each of these faint stars must be subdivided into thousands of wavelengths. The Keck/DEIMOS combination is the only one in the world capable of making these velocity measurements for large numbers of Andromeda stars.”

    The recently completed Panchromatic Hubble Andromeda Treasury (PHAT) survey provided high-resolution imaging at six different wavelengths for more than half of these stars, Dorman said. The study presents the velocity dispersion of young, intermediate-age, and old stars in the disk of Andromeda, the first such measurement in another galaxy.

    Dorman’s analysis revealed a clear trend related to stellar age, with the youngest stars showing relatively ordered rotational motion around the center of the Andromeda galaxy, while older stars displayed much more disordered motion. Stars in a “well ordered” population are all moving coherently, with nearly the same velocity, whereas stars in a disordered population have a wider range of velocities, implying a greater spatial dispersion.

    “If you could look at the disk edge-on, the stars in the well-ordered, coherent population would lie in a very thin plane, whereas the stars in the disordered population would form a much puffier layer,” Dorman explained.

    The researchers considered different scenarios of galactic disk formation and evolution that could account for their observations. One scenario involves the gradual disturbance of a well-ordered disk of stars as a result of mergers with small satellite galaxies. Previous studies have found evidence of such mergers in tidal streams of stars in the extended halo of Andromeda, which appear to be remnants of cannibalized dwarf galaxies. Stars from those galaxies can also accrete onto the disk, but accretion alone cannot account for the observed increase in velocity dispersion with stellar age, Dorman said.

    An alternate scenario involves the formation of the stellar disk from an initially thick, clumpy disk of gas that gradually settled. The oldest stars would then have formed while the gas disk was still in a puffed up and disordered configuration. Over time, the gas disk would have settled into a thinner configuration with more ordered motion, and the youngest stars would then have formed with the disk in that ordered configuration.

    According to Dorman, a combination of these mechanisms could account for the team’s observations. “Our findings should motivate theorists to carry out more detailed computer simulations of these scenarios,” she said.

    The comparison to the Milky Way revealed substantial differences suggesting that Andromeda has had a more violent accretion history in the recent past. “Even the most well ordered Andromeda stars are not as well ordered as the stars in the Milky Way’s disk,” Dorman said.

    In the currently favored “Lambda Cold Dark Matter” paradigm of structure formation in the universe, large galaxies such as Andromeda and the Milky Way are thought to have grown by cannibalizing smaller satellite galaxies and accreting their stars and gas. Cosmologists predict that 70 percent of disks the size of Andromeda’s and the Milky Way’s should have interacted with at least one sizable satellite in the last 10,000 years. The Milky Way’s disk is much too orderly for that to have happened, whereas Andromeda’s disk fits the prediction much better.

    “In this context, the motion of the stars in Andromeda’s disk is more normal, and the Milky Way may simply be an outlier with an unusually quiescent accretion history,” Guhathakurta said.

    Other researchers who collaborated with Dorman and Guhathakurta on this study include Anil Seth at the University of Utah; Daniel Weisz, Julianne Dalcanton, Alexia Lewis, and Benjamin Williams at the University of Washington; Karoline Gilbert at the Space Telescope Science Institute; Evan Skillman at the University of Minnesota; Eric Bell at the University of Michigan; and Katherine Hamren and Elisa Toloba at UC Santa Cruz. This research was funded by the National Science Foundation and NASA.

    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

     
  • richardmitnick 1:29 pm on December 16, 2014 Permalink | Reply
    Tags: , , , , , Keck Observatory   

    From ESO: “Journey to the Centre of the Milky Way Short Fulldome Planetarium Show” 


    European Southern Observatory

    What lies at the heart of our galaxy? For twenty years, ESO’s Very Large Telescope and the Keck telescopes have observed the centre of the Galaxy, looking at the motion of more than a hundred stars and identifying the position of an otherwise invisible object — the supermassive black hole at the centre of our galaxy.

    ESO VLT Interferometer
    ESO VLT Interior
    ESO/VLT

    Keck Observatory
    Keck Observatory Interior
    Keck

    Embark on a Journey to the Centre of the Milky Way and during seven minutes travel faster than light, from the driest place on Earth, the Atacama Desert in Chile right to the centre of our own galaxy, where a black hole is consuming anything that strays into its path. 84 million stars will appear in front of your eyes, each hiding mysteries waiting to be solved. Are there planets around them, perhaps with moons? Do they have water? Could they harbour life?

    Journey to the Centre of the Milky Way is the first fulldome planetarium mini-show produced in-house by ESO for its Planetarium and Visitor Centre, the ESO Supernova, due to open in 2017. Available for free in 4k resolution, the mini-show can be downloaded and used by any planetarium in the world.

    Watch, enjoy, learn.

    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 Main

    ESO, European Southern Observatory, builds and operates a suite of the world’s most advanced ground-based astronomical telescopes.

     
  • richardmitnick 3:01 pm on December 2, 2014 Permalink | Reply
    Tags: , , , , , , Keck Observatory   

    From Keck: “Scientists Accurately Quantify Dust Around Planets in Search for Life” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    December 2, 2014
    SCIENCE CONTACT:
    Bertrand Mennesson, PhD
    Jet Propulsion Laboratory
    (818)-354-0494
    bertrand.mennesson@jpl.nasa.gov

    MEDIA CONTACT
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    A new study from the Keck Interferometer, a former NASA project that combined the power of the twin W. M. Keck Observatory telescopes atop Mauna Kea, Hawaii, has brought exciting news to planet hunters. After surveying nearly 50 stars from 2008 to 2011, scientists have been able to determine with remarkable precision how much dust is around distant stars – a big step closer into finding planets than might harbor life. The discovery is being published in the Astrophysical Journal online, on December 8th.

    two
    Credit: NASA/JPL-Caltech
    A dusty planetary system (left) is compared to another system with little dust in this artist’s conception. Dust can make it difficult for telescopes to image planets because light from the dust can outshine that of the planets. Dust reflects visible light and shines with its own infrared, or thermal, glow. As the illustration shows, planets appear more readily in the planetary system shown at right with less dust. Research with the NASA-funded Keck Interferometer, a former NASA key science project that combined the power of the twin telescopes of the W. M. Keck Observatory atop Mauna Kea, Hawaii, shows that mature, sun-like stars appear to be, on average, not all that dusty. This is good news for future space missions wanting to take detailed pictures of planets like Earth and seek out possible signs of life.

    “This was really a mathematical tour de force,” said Peter Wizinowich, Interferometer Project Manager for Keck Observatory. “This team did something that we seldom see in terms of using all the available statistical techniques to evaluate the combined data set. They were able to dramatically reduce all the error bars, by a factor of 10, to really understand the amount of dust around these systems.”

    The Keck Interferometer was built to seek out this dust, and to ultimately help select targets for future NASA Earth-like planet-finding missions.

    Like planets, dust near a star is also hard to see. Interferometry is a high-resolution imaging technique that can be used to block out a star’s light, making the region nearby easier to observe. Light waves from the precise location of a star, collected separately by the twin 10-meter Keck Observatory telescopes, are combined and canceled out in a process called nulling.

    “If you don’t turn off the star, you are blinded and can’t see dust or planets,” said co-author Rafael Millan-Gabet of NASA’s exoplanet Science Institute at the California Institute of Technology in Pasadena, California, who led the Keck Interferometer’s science operations system.

    “Dust is a double-edged sword when it comes to imaging distant planets,” explained Bertrand Mennesson, lead author of the study who works at NASA’s Jet Propulsion Laboratory, Pasadena, California. “The presence of dust is a signpost for the planet formation process, but too much dust can block our view.” Mennesson has been involved in the Keck Interferometer project since its inception more than 10 years ago, both as a scientist and as the optics lead for one of its instruments.

    “Using the two Keck telescopes in concert and interfering their light beams, it is possible to distinguish astronomical objects much closer to each other than when using a single Keck telescope,” Mennesson said. “However, there is an additional difficulty when searching for warm dust in the immediate stellar environment: it generally contributes very little emission compared to the star, and that is when nulling interferometry comes into play.”

    In addition to requiring high performance from a large number of hardware and software subsystems, the nuller mode requires them to work smoothly together as a single, integrated system, according to Mark Colavita, the Keck Interferometer System Architect. “The nulling mode of the interferometer uses starlight across a wide range of wavelengths, including visible light for the adaptive optics to correct the telescope wave-fronts, near-infrared light to stabilize the path-lengths, and mid-infrared light for the nulling science measurements.”

    Planet Hunting

    Ground- and space-based telescopes have already captured images of exoplanets, or planets orbiting stars beyond our sun. These early images, which show giant planets in cool orbits far from the glow of their stars, represent a huge technological leap. The glare from stars can overwhelm the light of planets, like a firefly buzzing across the sun. So, researchers have developed complex instruments to block the starlight, allowing information about a planet’s shine to be obtained.

    The next challenge is to image smaller planets in the “habitable” zone around stars where possible life-bearing Earth-like planets outside the solar system could reside. Such a lofty goal may take decades, but researchers are already on the path to get there, developing new instruments and analyzing the dust kicked up around stars to better understand how to snap crisp planetary portraits. Scientists want to find out: Which stars have the most dust? And how dusty are the habitable zones of sun-like stars?

    In the latest study, nearly 50 mature, sun-like stars were analyzed with high precision to search for warm, room-temperature dust in their habitable zones. Roughly half of the stars selected for the study had previously shown no signs of cool dust circling in their outer reaches. This outer dust is easier to see than the inner, warm dust due to its greater distance from the star. Of this first group of stars, none were found to host the warm dust, making them good targets for planet imaging, and a good indication that other relatively dust-free stars are out there.

    The other stars in the study were already known to have significant amounts of distant cold dust orbiting them. In this group, many of the stars were found to also have the room-temperature dust. This is the first time a link between the cold and warm dust has been established. In other words, if a star is observed to have a cold belt of dust, astronomers can make an educated guess that its warm habitable zone is also riddled with dust, making it a poor target for imaging smaller planets in the ‘habitable zone’ around stars, or exo-Earths.

    “We want to avoid planets that are buried in dust,” said Mennesson.

    Like a busy construction site, the process of building planets is messy. It’s common for young, developing star systems to be covered in dust. Proto-planets collide, scattering dust. But eventually, the chaos settles and the dust clears – except in some older stars. Why are these mature stars still laden with warm dust in their habitable zones?

    The newfound link between cold and warm dust belts helps answer this question.

    “The outer belt is somehow feeding material into the inner warm belt,” said Geoff Bryden of JPL, a co-author of the study. “This transport of material could be accomplished as dust smoothly flows inward, or there could be larger cometary bodies thrown directly into the inner system.”

    The Keck Interferometer began construction in 1997, and finished its mission in 2012. It was developed by JPL, the Keck Observatory and the NASA Exoplanet Science Institute at Caltech. It was funded by NASA as a part of the Exoplanet Exploration Program with telescope and instrument operations managed by the W. M. Keck Observatory.

    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

     
  • richardmitnick 4:19 pm on November 26, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory   

    From Keck: “‘Eye of Sauron’ Provides New Way of Measuring Distances to Galaxies” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    November 26, 2014
    No Writer Credit

    A team of scientists, led by Dr. Sebastian Hoenig from the University of Southampton, has accurately measured the distance to the nearby NGC 4151 galaxy, using the W. M. Keck Observatory Interferometer. The team employed a new technique they developed, which allows them to measure precise distances to galaxies tens of millions of light years away. The research was published today in the journal Nature.

    Keck Interferometer
    Interferometry at Keck

    ngc
    NGC 4151
    This composite image shows the central region of the spiral galaxy NGC 4151, dubbed the “Eye of Sauron” by astronomers for its similarity to the eye of the malevolent character in The Lord of the Rings. In the “pupil” of the eye, X-rays (blue) from the Chandra X-ray Observatory are combined with optical data (yellow) showing positively charged hydrogen (“H II”) from observations with the 1-meter Jacobus Kapteyn Telescope on La Palma. The red around the pupil shows neutral hydrogen detected by radio observations with the NSF’s Very Large Array. This neutral hydrogen is part of a structure near the center of NGC 4151 that has been distorted by gravitational interactions with the rest of the galaxy, and includes material falling towards the center of the galaxy. The yellow blobs around the red ellipse are regions where star formation has recently occurred.
    Date 27 March 2008
    Source http://www.chandra.harvard.edu/photo/2011/n4151/
    Author X-ray: NASA/CXC/CfA/J.Wang et al.; Optical: Isaac Newton Group of Telescopes, La Palma/Jacobus Kapteyn Telescope, Radio: NSF/NRAO/VLA

    NASA Chandra Telescope
    NASA Chandra schematic
    NASA/Chandra

    Isaac Newton Jacobus Kapteyn Telescope Telescope
    Isaac Newton Jacobus Kapteyn Telescope interior
    Isaac Newton Jacobus Kapteyn Telescope

    NRAO VLA
    NRAO/VLA

    The new technique is similar to that used by land surveyors on earth, who measure both the physical and angular – or ‘apparent’ – size of a distant object, to calculate its distance from Earth.

    Previous reported distances to NGC 4151, which contains a supermassive black hole, ranged from 4- to 29-megaparsecs, but using this new, more accurate method, the researchers calculated the distance to the supermassive black hole as 19 megaparsecs.

    The galaxy NGC415 is dubbed the Eye of Sauron by astronomers for the similarity to its namesake in the film trilogy The Lord of the Rings. As in the famous saga, a ring plays a crucial role in this new measurement. All big galaxies in the universe host a supermassive black hole in their center and in about 10 percent of all galaxies, these supermassive black holes are growing by swallowing huge amounts of gas and dust from their surrounding environments. In this process, the material heats up and becomes very bright — becoming the most energetic sources of emission in the universe known as active galactic nuclei (AGN).

    This hot dust forms a ring around the supermassive black hole and emits infrared radiation, which the researchers used as the ruler. However, the apparent size of the Eye of Sauron’s ring is so small, the observations were carried out using the Keck Interferometer, which combines Keck Observatory’s twin 10-meter telescopes — already the largest telescopes on Earth — to achieve the resolving power of an 85m telescope.

    To measure the physical size of the dusty ring, the researchers measured the time delay between the emission of light from close to the black hole and the more distant infrared emission. The distance from the center to the hot dust is simply this delay divided by the speed of light.

    By combining the physical size of the dust ring with the apparent size measured with the Keck Interferometer, the researchers were able to determine a distance to NGC 4151.

    “One of the key findings is that the distance determined in this new fashion is quite precise — with 90 percent accuracy,” Hoenig said. “In fact, this method, based on simple geometrical principles, gives the most precise distances for remote galaxies. Moreover, it can be readily used on many more sources than current methods. Such distances are key in pinning down the cosmological parameters that characterize our universe or in accurately measuring black hole masses. Indeed, NGC 4151 is a key to calibrating various techniques of estimating black hole masses. Our new distance implies that these masses may have been systematically underestimated by 40 percent.”

    Hoenig, together with colleagues in Denmark and Japan, is currently setting up a new program to extend their work to many more AGN. The goal is to establish precise distances to a dozen galaxies using this technique and use them to constrain cosmological parameters to within few per cent. Combined with other measurements, this will provide a better understanding of the history of expansion of our universe.

    The Keck Interferometer began construction in 1997, and finished its mission in 2012. It was funded by NASA and managed by JPL. JPL is managed by Caltech for NASA.

    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.

    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

     
  • richardmitnick 2:24 pm on November 19, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory   

    From Keck: “Evicted? Possible Black Hole Found 2,600 Light Years from Home” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    November 19, 2014
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    An international team of researchers analyzing decades of observations from many facilities — including the W. M. Keck Observatory on Mauna Kea, the Pan-STARRS1 telescope on Haleakala and NASA’s Swift satellite — has discovered what appears to be a black hole booted from it’s host galaxy. The team was led by Michael Koss, who was a postdoctoral fellow at the Institute for Astronomy (IfA) at the University of Hawaii at Manoa during most of the time the study was ongoing. The study will be published in the Nov. 21 edition of Monthly Notices of the Royal Astronomical Society.

    ssd
    Credit: Credit: W. M. Keck Observatory/M. Koss (ETH Zurich) et al.
    Using the Keck II telescope in Hawaii, researchers obtained high-resolution images of Markarian 177 and SDSS1133 using a near-infrared filter. Twin bright spots in the galaxy’s central region are consistent with recent star formation, a disturbance that hints this galaxy may have merged with another.

    Pann-STARSR1 Telescope
    Pann-STARRS1 interior
    Pan-STARRS1 telescope

    NASA SWIFT Telescope
    NASA/Swift

    The mystery object is part of the dwarf galaxy Markarian 177, located in the bowl of the Big Dipper, a well-known star pattern within the constellation Ursa Major. Although supermassive black holes usually occupy galactic centers, SDSS1133 is located at least 2,600 light-years from its host galaxy’s core. The team was able to detect it in astronomical surveys dating back more than 60 years.

    In June 2013, the researchers obtained high-resolution near-infrared images of the object using the 10-meter Keck II telescope at Keck Observatory. “When we analyzed the Keck data, we found the emitting region of SDSS1133 is less than 40 light-years across, and that the center of Markarian 177 shows evidence of intense star formation and other features indicating a recent disturbance that matched what we expected for a recoiling black hole,” said Chao-Ling Hung, a UH Manoa graduate student performing the analysis of the Keck Observatory imaging in the study.

    “We suspect we’re seeing the aftermath of a merger of two small galaxies and their central black holes,” said co-author Laura Blecha, an Einstein Fellow in the University of Maryland’s Department of Astronomy and a leading theorist in simulating recoils, or “kicks,” in merging black holes. “Astronomers searching for recoiling black holes have been unable to confirm a detection, so finding even one of these sources would be a major discovery.”

    The collision and merger of two galaxies disrupts their shapes and results in new episodes of star formation. If each galaxy possesses a central supermassive black hole, they will form a bound binary pair at the center of the merged galaxy before ultimately coalescing themselves. “This study was extremely interesting for our research group because we typically study star formation and AGN activity that happens during the galaxy merger, but now we are looking for recoiling black holes after the merger,” said David Sanders, an IfA astronomer involved in the study.

    Merging black holes release a large amount of energy in the form of gravitational radiation, as explained by [Albert]Einstein’s theory of gravity. Waves in the fabric of space-time ripple outward in all directions from accelerating masses. If both black holes have equal masses and spins, their merger emits gravitational waves uniformly in all directions. More likely, masses and spins will be different, leading to lopsided gravitational wave emission that launches the black hole in the opposite direction.

    The kick may be strong enough to hurl the black hole entirely out of its home galaxy, fating it to forever drift through intergalactic space. More typically, a kick will send the object into an elongated orbit. Despite its relocation, the ejected black hole will retain any hot gas trapped around it and continue to shine until all of the gas is consumed as it moves along its new path.

    While the object’s unusual source of light in a galaxy some 90 million light-years away, its properties make it a good match for a supermassive black hole ejected from its home galaxy, astronomers can’t yet rule out an alternative possibility. The source, called SDSS1133, may be the remnant of a massive star that underwent a record period of eruptions before destroying itself in a supernova explosion.

    “With the data we have in hand, we can’t yet distinguish between these two scenarios,” Koss said, now an astronomer at ETH Zurich, the Swiss Federal Institute of Technology. “But, one exciting discovery made with NASA’s Swift is that the emission of ultraviolet light of SDSS1133 hasn’t changed for a decade, which is not something typically seen in a young supernova remnant.”

    To analyze the object in greater detail, the team is planning ultraviolet observations with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope in October 2015. “We found in the Pan-STARRS1 imaging that SDSS1133 has been getting significantly brighter at visible wavelengths over the last 6 months and that bolstered the black hole interpretation and our case to study SDSS1133 now with HST,” said Yanxia Li a UH Manoa graduate student involved in the analysis of the Pan-STARRS1 imaging in the study.

    NASA Hubble Cosmic Origins Spectograph
    COS on Hubble

    If SDSS1133 isn’t a black hole, then it must have been a very unusual type of star known as a Luminous Blue Variable (LBV). These stars undergo episodic eruptions that cast large amounts of mass into space long before they explode. Interpreted in this way, SDSS1133 would represent the longest period of LBV eruptions ever observed, followed by a terminal supernova explosion whose light reached Earth in 2001.

    The nearest analog in our galaxy is the massive binary system Eta Carinae, which includes an LBV containing about 90 times the sun’s mass. Between 1838 and 1845, the system underwent an outburst that ejected at least 10 solar masses and made it the second-brightest star in the sky. It then followed up with a smaller eruption in the 1890s.

    ec
    A huge, billowing pair of gas and dust clouds are captured in this stunning NASA Hubble Space Telescope image of the supermassive star Eta Carinae. Eta Carinae was observed by Hubble in September 1995 with the Wide Field and Planetary Camera 2 (WFPC2). Images taken through red and near-ultraviolet filters were subsequently combined to produce the color image shown. A sequence of eight exposures was necessary to cover the object’s huge dynamic range: the outer ejecta blobs are 100,000 times fainter than the brilliant central star. Eta Carinae suffered a giant outburst about 160 years ago, when it became one of the brightest stars in the southern sky. Though the star released as much visible light as a supernova explosion, it survived the outburst. The explosion produced two lobes and a large, thin equatorial disk, all moving outward at about 1 million kilometers per hour.
    Date 10 June 1996
    Author Nathan Smith (University of California, Berkeley), and NASA

    NASA Hubble WFPC2
    WFPC2 (no longer in service)

    For an LBV to explain SDSS1133, the star must have been in nearly continual eruption from at least 1950 to 2001, when it reached peak brightness and went supernova. The spatial resolution and sensitivity of telescopes prior to 1950 were insufficient to detect the source. But if this was an LBV eruption, the current record already shows it to be the longest and most persistent one ever observed. An interaction between the ejected gas and the explosion’s blast wave could explain the object’s steady brightness in the ultraviolet.

    Whether it’s a rogue supermassive black hole or the closing act of a rare star, it seems astronomers have never seen the likes of SDSS1133 before.

    NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    Keck NIRC2
    NIRC2

    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

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 3:02 pm on November 12, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory   

    From UCO KECK: “Astronomers Thrilled by Extreme Storms on Uranus” 

    Keck Observatory

    Keck Observatory

    UCO Keck Observatory

    November 12, 2014
    SCIENCE CONTACTS
    Imke de Pater
    imke@berkeley.edu

    Larry Sromovsky
    larry.sromovsky@ssec.wisc.edu

    Heidi Hammel
    (203) 321-6929
    hbhammel@aura-astronomy.org

    Marc Delcroix
    delcroix.marc@free.fr

    MEDIA CONTACT:
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    The normally bland face of Uranus has become increasingly stormy, with enormous cloud systems so bright that for the first time ever, amateur astronomers are able to see details in the planet’s hazy blue-green atmosphere.

    “The weather on Uranus is incredibly active,” said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley, and leader of the team that first noticed the activity when observing the planet with adaptive optics on the W. M. Keck Observatory in Hawaii.

    “This type of activity would have been expected in 2007, when Uranus’s once every 42-year equinox occurred and the sun shined directly on the equator,” noted co-investigator Heidi Hammel of the Association of Universities for Research in Astronomy. “But we predicted that such activity would have died down by now. Why we see these incredible storms now is beyond anybody’s guess.”

    In all, de Pater, Hammel and their team detected eight large storms on Uranus’s northern hemisphere when observing the planet with the Keck Observatory on August 5 and 6. One was the brightest storm ever seen on Uranus at 2.2 microns, a wavelength that senses clouds just below the tropopause, where the pressure ranges from about 300 to 500 mbar, or half the pressure at Earth’s surface. The storm accounted for 30 percent of all light reflected by the rest of the planet at this wavelength.

    ur
    Infrared images of Uranus (1.6 and 2.2 microns) obtained on Aug. 6, 2014, with adaptive optics on the 10-meter Keck II telescope. The white spot is an extremely large storm that was brighter than any feature ever recorded on the planet in the 2.2 micron band. The cloud rotating into view at the lower-right limb grew into the large storm that was seen by amateur astronomers at visible wavelengths. Credit: Imke de Pater (UC Berkeley) & W. M. Keck Observatory images.

    gif
    Animation showing the movement of the bright spot as Uranus rotated over a two hour period on Oct. 4, 2014. The images were taken at the Pic du Midi telescope in the French Pyrénées.
    Courtesy of Marc Delcroix and F. Colas (S2P).

    3
    Optical images of Uranus on Sept. 19 and Oct. 2, showing the dramatic appearance of a bright storm on a planet that normally displays only a diffuse bright polar region.
    Credit: Courtesy of Anthony Wesley, Murrumbateman, Australia

    When amateur astronomers heard about the activity, they turned their telescopes on the planet and were amazed to see a bright blotch on the surface of a normally boring blue dot.

    ‘I got it!’

    French amateur astronomer Marc Delcroix processed the amateur images and confirmed the discovery of a bright spot on an image by French amateur Régis De-Bénedictis, then in others taken by fellow amateurs in September and October. He had his own chance on Oct. 3 and 4 to photograph it with the Pic du Midi one-meter telescope, where on the second night, “I caught the feature when it was transiting, and I thought, ‘Yes, I got it!’” said Delcroix.

    “I was thrilled to see such activity on Uranus. Getting details on Mars, Jupiter or Saturn is now routine, but seeing details on Uranus and Neptune are the new frontiers for us amateurs and I did not want to miss that,” said Delcroix, who works for an auto parts supplier in Toulouse and has been observing the skies – Jupiter in particular – with his backyard telescope since 2006 and, since 2012, occasionally with the Pic du Midi telescope. “I was so happy to confirm myself these first amateur images on this bright storm on Uranus, feeling I was living a very special moment for planetary amateur astronomy.”Interestingly, the extremely bright storm seen by the 10-meter Keck II telescope in the near infrared is not the one seen by the amateurs, which is much deeper in the atmosphere than the one that initially caused all the excitement. De Pater’s colleague Larry Sromovsky, a planetary scientist at the University of Wisconsin, Madison, identified the amateur spot as one of the few features on the Keck Observatory images from August 5 that was only seen at 1.6 microns, and not at 2.2 microns. The 1.6 micron light is emitted from deeper in the atmosphere, which means that this feature is below the uppermost cloud layer of methane-ice in Uranus’s atmosphere.

    “The colors and morphology of this cloud complex suggests that the storm may be tied to a vortex in the deeper atmosphere similar to two large cloud complexes seen during the equinox,” Sromovsky said

    Such vortices could be anchored much deeper in the atmosphere and extend over large vertical distances, as inferred from similar vortices on Jupiter, including its Great Red Spot.

    An expanded team of astronomers led by Kunio M. Sayanagi, an Assistant Professor at Hampton University in Virginia, leveraged the amateur observations to activate a “Target of Opportunity” proposal on the Hubble Space Telescope, which imaged the entire planet on Oct. 14. Observing at a variety of wavelengths, HST revealed multiple storm components extending over a distance of more than 9,000 kilometers (5,760 miles) and clouds at a variety of altitudes.

    NASA Hubble Telescope
    NASA Hubble schematic
    NASA/ESA Hubble

    De Pater, Sromovsky, Hammel and Pat Fry of the University of Wisconsin will report the details of their observations on Nov. 12 at a meeting of the American Astronomical Society’s Division of Planetary Sciences in Tucson, Ariz.

    Ice giant

    Uranus is an ice giant, about four times the diameter of Earth, with an atmosphere of hydrogen and helium, with just a bit of methane to give it a blue tint. Because it is so distant – 19 times farther from the sun than Earth – astronomers were able to see little detail on its surface until adaptive optics on both Keck Observatory telescopes revealed features much like those on Jupiter.

    De Pater and her colleagues have been following Uranus for more than a decade, charting the weather on the planet, including bands of circulating clouds, massive swirling storms and convective features at its north pole. Bright clouds are probably caused by gases such as methane rising in the atmosphere and condensing into highly reflective clouds of methane ice.

    Because Uranus has no internal source of heat, its atmospheric activity was thought to be driven solely by sunlight, which is now weak in the northern hemisphere. Hence astronomers were surprised when these observations showed such intense activity.

    Observations taken with the Keck II telescope by Christoph Baranec, an Assistant Professor at the University of Hawaii on Manoa, revealed that the storm was still active, but had a different morphology and possibly reduced intensity.

    “If indeed these features are high-altitude clouds generated by flow perturbations associated with a deeper vortex system, such drastic fluctuations in intensity would indeed be possible,” Sromovsky added.

    “These unexpected observations remind us keenly of how little we understand about atmospheric dynamics in outer planet atmospheres,” the authors wrote in their paper.

    NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    Keck NIRC2
    NIRC2

    See the full article here.

    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

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 6:20 pm on November 3, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory   

    From Keck: “Mysterious G2 Cloud Near Black Hole Identified” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    November 3, 2014
    Media Contact
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808.881.3827
    sjefferson@keck.hawaii.edu

    The mystery about a thin, bizarre object in the center of the Milky Way headed toward our galaxy’s enormous black hole has been solved by UCLA astronomers using the W. M. Keck Observatory, home of the two largest telescopes on Earth. The scientists studied the object, known as G2, during its closest approach to the black hole this summer, and found the black hole did not dine on it. The research is published today in the journal Astrophysical Journal Letters.

    While some scientists believed the object was a cloud of hydrogen gas that would be torn apart in a fiery show, [Andrea]Ghez and her team proved it was much more interesting.

    “G2 survived and continues happily on its orbit; a gas cloud would not do that,” said Andrea Ghez, UCLA professor of physics and astronomy who holds the Lauren B. Leichtman and Arthur E. Levine Chair in Astrophysics, and directs the UCLA Galactic Center Group. “G2 was completely unaffected by the black hole; no fireworks.”

    Instead, the team has demonstrated it is a pair of binary stars that had been orbiting the black hole in tandem and merged together into an extremely large star, cloaked in gas and dust, and choreographed by the black hole’s powerful gravitational field.

    “G2 is not alone,” said Ghez, who uses Keck Observatory to study thousands of stars in the neighborhood of the supermassive black hole. “We’re seeing a new class of stars near the black hole, and as a consequence of the black hole.”

    Ghez and her colleagues — who include lead author Gunther Witzel, a UCLA postdoctoral scholar in Ghez’s research group, and Mark Morris, a UCLA professor of physics and astronomy — studied the event with both of the 10-meter telescopes at Keck Observatory.

    Keck Observatory employs a powerful technology called adaptive optics, which Ghez helped to pioneer, to correct the distorting effects of the Earth’s atmosphere in real time, and to reveal the region of space around the black hole. With adaptive optics, Ghez and her colleagues have revealed many surprises about the environments surrounding supermassive black holes, discovering, for example, young stars where none were expected and seeing a lack of old stars where many were anticipated.

    “The Keck Observatory has been the leader in adaptive optics for more than a decade and has enabled us to achieve tremendous progress in correcting the distorting effects of the Earth’s atmosphere using high–angular resolution imaging techniques,” Ghez said.

    The researchers wouldn’t have been able to arrive at their conclusions without the Keck’s advanced technology. “It is a result that in its precision was possible only with these incredible tools, the Keck Observatory’s 10-meter telescopes,” Witzel said.

    “We are seeing phenomena about black holes that you can’t watch anywhere else in the universe,” Ghez added. “We are starting to understand the physics of black holes in a way that has never been possible before, and is possible only at the center of the galaxy.”

    Massive stars in our galaxy, she noted, primarily come in pairs. When the two stars merge into one, the star expands for more than one million years “before it settles back down,” Ghez said. “This may be happening more than we thought; the stars at the center of the galaxy are massive and mostly binaries. It’s possible that many of the stars we’ve been watching and not understanding may be the end product of a merger that are calm now.”

    G2, in that explosive stage now, has been an object of fascination. “Its closest approach to the black hole was one of the most watched events in astronomy in my career,” Ghez said.

    G2 makes an unusual, 300-year elliptical orbit around the black hole and Ghez’s group calculated its closest approach occurred this summer — later than other astronomers believed —and they were in place at Keck Observatory to gather the data.

    Black holes, which form out of the collapse of matter, have such high density that nothing can escape their gravitational pull, not even light. They cannot be seen directly, but their influence on nearby stars is visible and provides a signature, said Ghez, a 2008 MacArthur Fellow.

    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 Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectographs and world-leading laser guide star adaptive optics systems.

    NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    Keck NIRC2
    Keck’s NIRC2

    NASA Hubble Telescope
    NASA/ESA Hubble

    See the full article here.

    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

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
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
Follow

Get every new post delivered to your Inbox.

Join 425 other followers

%d bloggers like this: