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  • richardmitnick 2:06 pm on October 16, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory, Max Planck Institute for Astronomy   

    From Keck: “Scientists Build First Map of Hidden Universe” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    October 15, 2014
    Khee-Gan Lee
    Max Planck Institute for Astronomy
    Heidelberg, Germany
    Phone: (+49|0) 6221 –528 467
    email: lee@mpia.de

    Joe Hennawi
    Max Planck Institute for Astronomy
    Heidelberg, Germany
    Phone: (+49|0) 6221 –528 263
    email: joe@mpia.de

    MEDIA CONTACTS:
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    Phone: (808)881-3827
    email: sjefferson@keck.hawaii.edu

    Dr. Markus Pössel
    Public Information Officer
    Max Planck Institute for Astronomy
    Heidelberg, Germany
    Phone: (+49|0) 6221 –528 261
    email: pr@mpia.de

    A team led by astronomers from the Max Planck Institute for Astronomy has created the first three-dimensional map of the ‘adolescent’ Universe, just 3 billion years after the Big Bang. This map, built from data collected from the W. M. Keck Observatory, is millions of light-years across and provides a tantalizing glimpse of large structures in the ‘cosmic web’ – the backbone of cosmic structure.

    map
    3D map of the cosmic web at a distance of 10.8 billion light years from Earth. The map was generated from imprints of hydrogen gas observed in the spectrum of 24 background galaxies, which are located behind the volume being mapped. This is the first time that large-scale structures in such a distant part of the Universe have been mapped directly. The coloring represents the density of hydrogen gas tracing the cosmic web, with brighter colors representing higher density. Credit: Casey Stark (UC Berkeley) and Khee-Gan Lee (MPIA)

    more

    On the largest scales, matter in the Universe is arranged in a vast network of filamentary structures known as the ‘cosmic web’, its tangled strands spanning hundreds of millions of light-years. Dark matter, which emits no light, forms the backbone of this web, which is also suffused with primordial hydrogen gas left over from the Big Bang. Galaxies like our own Milky Way are embedded inside this web, but fill only a tiny fraction of its volume.

    Now a team of astronomers led by Khee-Gan Lee, a post-doc at the Max Planck Institute for Astronomy, has created a map of hydrogen absorption revealing a three-dimensional section of the universe 11 billions light years away – the first time the cosmic web has been mapped at such a vast distance. Since observing to such immense distances is also looking back in time, the map reveals the early stages of cosmic structure formation when the Universe was only a quarter of its current age, during an era when the galaxies were undergoing a major ‘growth spurt’.

    The map was created by using faint background galaxies as light sources, against which gas could be seen by the characteristic absorption features of hydrogen. The wavelengths of each hydrogen feature showed the presence of gas at a specific distance from us. Combining all of the measurements across the entire field of view allowed the team a tantalizing glimpse of giant filamentary structures extending across millions of light-years, and paves the way for more extensive studies that will reveal not only the structure of the cosmic web, but also details of its function – the ways that pristine gas is funneled along the web into galaxies, providing the raw material for the formation of galaxies, stars, and planets.

    Using the light from faint background galaxies for this purpose had been thought impossible with current telescopes – until Lee carried out calculations that suggested otherwise. To ensure success, Lee and his colleagues obtained observing time at Keck Observatory, home of the two largest and most scientifically productive telescopes in the world.

    Although bad weather limited the astronomers to observing for only 4 hours, the data they collected with the LRIS instrument was completely unprecedented. “We were pretty disappointed as the weather was terrible and we only managed to collect a few hours of good data. But judging by the data quality as it came off the telescope, it was clear to me that the experiment was going to work,” said Max Plank’s Joseph Hennawi, who was part of the observing team.

    Keck LRIS
    Keck’s LRIS

    “The data were obtained using the LRIS spectrograph on the Keck I telescope,” Lee said. “With its gargantuan 10m-diameter mirror, this telescope effectively collected enough light from our targeted galaxies that are more than 15 billion times fainter than the faintest stars visible to the naked eye. Since we were measuring the dimming of blue light from these distant galaxies caused by the foreground gas, the thin atmosphere at the summit of Mauna Kea allowed more of this blue light to reach the telescope and be measured by the highly sensitive detectors of the LRIS spectrograph. The data we collected would have taken at least several times longer to obtain on any other telescope.”

    Their absorption measurements using 24 faint background galaxies provided sufficient coverage of a small patch of the sky to be combined into a 3D map of the foreground cosmic web. A crucial element was the computer algorithm used to create the 3D map: due to the large amount of data, a naïve implementation of the map-making procedure would require an inordinate amount of computing time. Fortunately, team members Casey Stark and Martin White (UC Berkeley and Lawrence Berkeley National Lab) devised a new fast algorithm that could create the map within minutes. “We realized we could simplify the computations by tailoring it to this particular problem, and thus use much less memory. A calculation that previously required a supercomputer now runs on a laptop”, says Stark.

    The resulting map of hydrogen absorption reveals a three-dimensional section of the universe 11 billions light years away – this is first time the cosmic web has been mapped at such a vast distance. Since observing to such immense distances is also looking back in time, the map reveals the early stages of cosmic structure formation when the Universe was only a quarter of its current age, during an era when the galaxies were undergoing a major ‘growth spurt’. The map provides a tantalizing glimpse of giant filamentary structures extending across millions of light-years, and paves the way for more extensive studies that will reveal not only the structure of the cosmic web, but also details of its function – the ways that pristine gas is funneled along the web into galaxies, providing the raw material for the formation of galaxies, stars, and planets.

    The Low Resolution Imaging Spectrometer (LRIS) is a very versatile visible-wavelength imaging and spectroscopy instrument commissioned in 1993 and operating at the Cassegrain focus of Keck I. Since it has been commissioned it has seen two major upgrades to further enhance its capabilities: addition of a second, blue arm optimized for shorter wavelengths of light; and the installation of detectors that are much more sensitive at the longest (red) wavelengths. Each arm is optimized for the wavelengths it covers. This large range of wavelength coverage, combined with the instrument’s high sensitivity, allows the study of everything from comets (which have interesting features in the ultraviolet part of the spectrum), to the blue light from star formation, to the red light of very distant objects. LRIS also records the spectra of up to 50 objects simultaneously, especially useful for studies of clusters of galaxies in the most distant reaches, and earliest times, of the universe.

    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.
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  • richardmitnick 2:57 pm on August 4, 2014 Permalink | Reply
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    From Keck: “Keck, Gemini Observatories Reveal Massive Eruptions on Io” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    August 4, 2014
    Media Contact:

    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    808-881-3827
    sjefferson@keck.hawaii.edu

    Science Contacts:

    Imke de Pater
    510-643-7673
    mke@berkeley.edu

    Ashley Davies
    818-393-1775
    ashley.davies@jpl.nasa.gov

    Katherine de Kleer
    kdekleer@astro.berkeley.edu

    Three massive volcanic eruptions occurred on Jupiter’s moon Io within a two-week period last August, leading astronomers to speculate that these presumed rare “outbursts,” which can send material hundreds of miles above the surface, might be much more common than astronomers thought. The observations were made using the W. M. Keck Observatory and Gemini Observatory, both near the summit of Mauna Kea, Hawaii.

    Gemini North telescope
    Gemini North

    mess
    mages of Io obtained at different infrared wavelengths (in microns, μm, or millionths of a meter) with the W. M. Keck Observatory’s 10-meter Keck II telescope on Aug. 15, 2013 (a-c) and the Gemini North telescope on Aug. 29, 2013 (d). The bar on the right of each image indicates the intensity of the infrared emission. Note that emissions from the large volcanic outbursts on Aug. 15 at Rarog and Heno Paterae have substantially faded by Aug. 29. A second bright spot is visible to the north of the Rarog and Heno eruptions in c and to the west of the outburst in d. This hot spot was identified as Loki Patera, a lava lake that appeared to be particularly active at the same time. An even brighter outburst is seen to the lower right in panel (d), labeled “201308C” and is one of the most powerful outbursts ever seen on Io. Credit: Imke de Pater and Katherine de Kleer, UC Berkeley.

    “We typically expect one huge outburst every one or two years, and they’re usually not this bright,” said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley, and lead author of one of two papers describing the eruptions. “Here we had three extremely bright outbursts, which suggest that if we looked more frequently we might see many more of them on Io.”

    Io, the innermost of Jupiter’s four large “Galilean” moons, is about 2,300 miles across, and, aside from Earth, is the only known place in the solar system with volcanoes erupting extremely hot lava like that seen on Earth. Because of Io’s low gravity, large volcanic eruptions produce an umbrella of debris that rises high into space.

    De Pater’s long-time colleague and coauthor Ashley Davies, a volcanologist with NASA’s Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, Calif., said that the recent eruptions resemble past events that spewed tens of cubic miles of lava over hundreds of square miles in a short period of time.

    “These new events are in a relatively rare class of eruptions on Io because of their size and astonishingly high thermal emission,” he said. “The amount of energy being emitted by these eruptions implies lava fountains gushing out of fissures at a very large volume per second, forming lava flows that quickly spread over the surface of Io.”

    All three events, including the largest, most powerful eruption of the trio on 29 Aug. 2013, were likely characterized by “curtains of fire,” as lava blasted out of fissures perhaps several miles long.

    The papers, one with lead author Katherine de Kleer, a UC Berkeley graduate student, and coauthored by UC Berkeley research astronomer Máté Ádámkovics, and the other coauthored by Ádámkovics and David R. Ciardi of Caltech’s NASA Exoplanet Science Institute, have been accepted for publication in the journal Icarus.

    Lava fountains on Io

    De Pater discovered the first two massive eruptions on Aug. 15, 2013, using the near-infrared camera (NIRC2) coupled to the adaptive optics system on the Keck II telescope, one of two 10-meter telescopes operated by the W. M. Keck Observatory in Hawaii. The brightest, at a caldera named Rarog Patera, was calculated to have produced a 50 square-mile, 30-foot thick lava flow, while the other, close to another caldera called Heno Patera, produced flows covering 120 square miles. Both were located in Io’s southern hemisphere, near its limb, and were nearly gone when imaged five days later.

    Keck Observatory NIRC2
    Keck/NIRC2

    De Pater discovered a third and even brighter eruption — one of the brightest ever seen on Io — on Aug. 29 at the start of a year-long series of Io observations led by de Kleer, using both the Near-Infrared Imager with adaptive optics on the Gemini North telescope on Mauna Kea, and the SpeX near-infrared spectrometer on NASA’s nearby Infrared Telescope Facility (IRTF). De Kleer used the fortuitous detection of this outburst simultaneously at Gemini and the IRTF to show that the eruption temperature is likely much higher than typical eruption temperatures on Earth today, “indicative of a composition of the magma that on Earth only occurred in our planet’s formative years,” de Kleer said.

    At the time of the observation, the thermal source had an area of up to 32 square miles. The modelled temperature of the lava indicated it had barely had time to cool, suggesting that the event was dominated by lava fountains.

    “We are looking at several cubic miles of lava in rapidly emplaced flows,” said Davies, who has developed models to predict the volume of magma erupted based on spectroscopic observations. “This will help us understand the processes that helped shape the surfaces of all the terrestrial planets, including Earth, and the moon.”

    The team tracked the heat of the third outburst for almost two weeks after its discovery to investigate how volcanoes influence Io’s atmosphere and how these eruptions feed a doughnut of ionized gas – the Io plasma torus – that surrounds Jupiter near Io’s orbit. De Kleer timed her Gemini and IRTF observations to coincide with observations of the plasma torus by the Japanese HISAKI (SPRINT-A) spacecraft, which is in orbit around Earth, so she can correlate the different data sets.

    Hisaki JAXA Japanese spacecraft
    Japanese HISAKI (SPRINT-A) spacecraft

    A volcanic laboratory

    Volcanoes were first noted on Io in 1979, and subsequent studies by the Galileo spacecraft, which first flew by Io in 1996, and ground-based telescopes show that eruptions and lava fountains occur constantly, creating rivers and lakes of lava. But large eruptions, creating vast lava flows in some cases thousands of square miles in area, were thought to be rare. Only 13 were observed between 1978 and 2006, in part because only a handful of astronomers, de Pater among them, regularly scan the moon.

    NASA Galileo
    NASA/Galileo

    Davies’ interest in Io’s volcanoes arises from the moon’s resemblance to an early Earth when heat from the decay of radioactive elements — much more intense than radiogenic heating today — created exotic, high-temperature lavas. Io remains volcanically active for a different reason — Jupiter and the moons Europa and Ganymede constantly tug on it — but the current eruptions on Io are likely similar to those that shaped the surfaces of inner solar system planets such as Earth and Venus in their youth.

    “We are using Io as a volcanic laboratory, where we can look back into the past of the terrestrial planets to get a better understanding of how these large eruptions took place, and how fast and how long they lasted,” Davies said.

    In a third paper accepted by Icarus, de Pater, Davies and their colleagues summarize a decade of Io observations with the Keck II and Gemini telescopes. Their map of the surface of Io pinpointed more than two dozen hot spots whose spatial distribution changed significantly between 2001 and 2010. In 2010 the hot spots were dominated by two volcanic centers: Loki Patera, an extremely large active lava lake on Io, and Kanehekili Fluctus, an area of continuing pahoehoe lava flows.

    The team hopes that monitoring Io’s surface annually will reveal the style of volcanic eruptions on the moon, constrain the composition of the magma, and accurately map the spatial distribution of the heat flow and potential variations over time. This information is essential to get a better understanding of the physical processes involved in the heating and cooling processes on Io, de Pater said.

    The work is funded by the National Science Foundation and NASA’s Outer Planets Research and Planetary Geology and Geophysics Programs.

    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.
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  • richardmitnick 3:58 am on July 3, 2014 Permalink | Reply
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    From Keck- “NGC 4651: The Umbrella Galaxy” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    Spiral galaxy NGC 4651 is a mere 62 million light-years distant, toward the well-groomed northern constellation Coma Berenices.

    ngc4651

    About the size of our Milky Way, this island universe is seen to have a faint umbrella-shaped structure that seems to extend (left) some 100 thousand light-years beyond the bright galactic disk. The giant cosmic umbrella is now known to be composed of tidal star streams – extensive trails of stars gravitationally stripped from a smaller satellite galaxy. The small galaxy was eventually torn apart in repeated encounters as it swept back and forth on eccentric orbits through NGC 4651. In fact, the picture insert zooms in on the smaller galaxy’s remnant core, identified in an extensive exploration of the system, using data from the large Subaru and Keck telescopes on Mauna Kea. Work begun by a remarkable collaboration of amateur and professional astronomers to image faint structures around bright galaxies suggests that even in nearby galaxies, tidal star streams are common markers of such galactic mergers. The result is explained by models of galaxy formation that also apply to our own Milky Way.

    NAOJ Subaru Telescope
    NAOJ Subaru telescope

    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.
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  • richardmitnick 12:59 pm on June 24, 2014 Permalink | Reply
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    From Keck: “Planet Found with an 80,000-Year Orbit” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    May 14, 2014
    Science Contact
    Marie-Ève Naud
    CRAQ – Université de Montréal
    514 343-6111, ext 3797
    naud@astro.umontreal.ca

    Media Contact
    Steve Jefferson
    W. M. Keck Observatory
    808-881-3827
    sjefferson@keck.hawaii.edu

    A team of researchers has discovered and photographed a gas giant only 155 light years from our solar system, adding to the short list of exoplanets discovered through direct imaging. It is located around GU Psc, a star with one-third the mass of the Sun and located in the constellation Pisces. See the article in The Astrophysical Journal.

    planet
    This direct image was taken at Keck Observatory using NIRC2 and Laser Guide Star Adaptive Optics showing the planet does not have a binary companion.

    The international research team, led by Marie-Ève Naud, a PhD student in the Department of Physics at the Université de Montréal, was able to find this planet by combining observations from the the Gemini Observatory, the Observatoire Mont-Mégantic (OMM), the Canada-France-Hawaii Telescope (CFHT) and the W. M. Keck Observatory.

    Gemini South telescope
    Gemini South

    OMM Telescope
    OMM

    Canada-France-Hawaii Telescope
    Canada-France Hawaii Telescope

    A distant planet that can be studied in detail

    The object was discovered using Gemini-South and followed-up with Gemini-North spectroscopy and CFHT photometry. Once Naud’s team had the entire spectrum, they realized the object had a very low temperature, with properties similar to substellar objects like brown dwarfs or planets.

    One possibility was that the object had a peculiar spectrum simply from its youth, and that this had nothing to do with it being a binary, but the other tantalizing possibility was it was a binary planet, with one component being slightly warmer than the team derived from their analysis and the other component slightly cooler.

    “This would have been the first ever planetary-mass binary, making our object even more of an oddity,” said Étiene Artigau, co-supervisor of Naud’s thesis and astrophysicist at the Université de Montréal. The team obtained Laser Guide Star Adaptive Optics observations using NIRC2 at Keck Observatory to determine it was a single planet.

    GU Psc b is around 2,000 times the Earth-Sun distance from its star, a record among exoplanets. Given this distance, it takes approximately 80,000 Earth years for GU Psc b to make a complete orbit around its star. The researchers took advantage of the large distance between the planet and its star to obtain images. By comparing images obtained in different wavelengths (colors) from the OMM and CFHT, they were able to characterize the planet.

    “Planets are much brighter when viewed in infrared rather than visible light, because their surface temperature is lower compared to other stars,” Naud said

    Knowing where to look

    The researchers were looking around GU Psc because the star had just been identified as a member of the young star group associated with AB Doradus. Young stars (only 100 million years old) are prime targets for planetary detection through imaging because the planets around them are still flush with the heat of their formation and are therefore brighter. This does not mean that planets similar to GU Psc b exist in large numbers, said Artigau. “We observed more than 90 stars and found only one planet, so this is truly an astronomical oddity,” he said.

    Astronomers do not directly measure the mass of a planet or star. Instead, researchers use theoretical models to determine their characteristics. The light spectrum of GU Psc b obtained from the Gemini North telescope in Hawaii was compared to such models to show that it has a temperature of around 800°C. Knowing the age of GU Psc due to its location in the AB Doradus group, the team was able to determine its mass, which is 9-13 times that of Jupiter.

    “GU Psc b is a true gift of nature,” said says René Doyon, co-supervisor of Naud’s thesis and OMM Director. “The large distance that separates it from its star allows it to be studied in depth with a variety of instruments, which will provide a better understanding of giant exoplanets in general.”

    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 spectroscopy 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 Observatory 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


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  • richardmitnick 6:59 pm on June 3, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory   

    From Keck: “Ancient Worlds from Another Galaxy Discovered Next Door” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    June 3, 2014
    Media Contact:

    Neha Okhandiar
    Public Relations Manager – Science and Engineering
    T: +44 (0)207 882 7927
    E: n.okhandiar@qmul.ac.uk

    Steve Jefferson
    Communications Officer, W. M. Keck Observatory
    T: (808)881-3827
    E: sjefferson@keck.hawaii.edu

    An international team of scientists, led by astronomers at Queen Mary University of London, report of two new planets orbiting Kapteyn’s star, one of the oldest stars found near the Sun. One of the newly-discovered planets could be ripe for life as it orbits at the right distance to the star to allow liquid water on its surface. The paper is being published by the Monthly Notices of the Royal Astronomical Society on June 4.

    Dutch astronomer Jacobus Kapteyn discovered the star at the end of the 19th century. It is the second fastest moving star in the sky and belongs to the galactic halo, an extended cloud of stars orbiting our galaxy. With a third of the mass of the sun, this red-dwarf can be seen in the southern constellation of Pictor with an amateur telescope.

    The astronomers used new data from the 3.6 meter La Silla Observatory in Chile to measure tiny periodic changes in the motion of the star, and followed up with two more high-precision spectrometers to secure the detection: W. M. Keck Observatory’s HIRES instrument installed on the 10-meter Keck I telescope on the summit of Mauna Kea, and PFS at the 6.5 meter Las Campanas Observatory in Chile.

    ESO 3.6m telescope & HARPS at LaSilla
    ESO 3.6m telescope at LaSilla

    Magellan 6.5 meter telescopes
    6.5m Magellan telescopes

    Using the Doppler Effect, which shifts the star’s light spectrum depending on its velocity, the scientists can work out some properties of these planets, such as their masses and periods of orbit.

    “We were surprised to find planets orbiting Kapteyn’s star,” said Dr Guillem Anglada-Escude, from QMUL’s School of Physics and Astronomy. “Previous data showed some moderate excess of variability, so we were looking for very short period planets when the new signals showed up loud and clear.”

    Paul Butler and I have been obtaining precision radial velocity data of Kapteyn’s star for over a decade at Keck, and were thus heavily invested in this work,” said Steve Vogt, a professor of astronomy at the University of California, Santa Cruz that contributed the data from Keck Observatory. “This quite southerly star was quite a tough stretch though from Keck, as the star never gets higher than 26 degrees altitude. Fortunately, Mauna Kea has excellent seeing and a clear view all the way to the southern horizon.”

    “The discovery of planets around this star are the hard-won fruit of many years of patient, careful acquisition of high precision data from the very stable HIRES instrument on Keck,” said Paul Butler, astronomer with Carnegie Institution for Science that works with Vogt. “Our success was also due, in no small part, to the efforts of the excellent Keck staff that keep this complex facility finely-tuned year in and year out.”

    Based on the data collected, the planet Kapteyn b might support liquid water as its mass is at least five times that of Earth’s and orbits the star every 48 days. The second planet, Kapteyn c is a massive super-Earth in comparison: its year lasts for 121 days and astronomers think it’s too cold to support liquid water.

    At the moment, only a few properties of the planets are known: approximate masses, orbital periods, and distances to the star. By measuring the atmosphere of these planets with next-generation instruments, scientists will try to find out whether they can support liquid water.

    Typical planetary systems detected by NASA’s Kepler mission are hundreds of light-years away. In contrast, Kapteyn’s star is only 13 light years away from Earth and is the 25th nearest star to the Sun.

    Kapteyn’s star was born in a dwarf galaxy absorbed and disrupted by the early Milky Way. This galactic disruption event put the star in its fast halo orbit. The likely remnant core of the original dwarf galaxy is Omega Centauri, an enigmatic globular cluster 16,000 light years from Earth which contains hundreds of thousands of similarly old suns. This sets the most likely age of the planets at 11.5 billion years, which is 2.5 times older than Earth and 2 billion years younger than the universe itself (around 13.7 billion years).

    Omega Centauri
    Omega Centauri
    The globular cluster Omega Centauri — with as many as ten million stars — is seen in all its splendour in this image captured with the WFI camera from ESO’s La Silla Observatory. The image shows only the central part of the cluster — about the size of the full moon on the sky (half a degree). North is up, East is to the left. This colour image is a composite of B, V and I filtered images. Note that because WFI is equipped with a mosaic detector, there are two small gaps in the image which were filled with lower quality data from the Digitized Sky Survey.

    “It does make you wonder what kind of life could have evolved on those planets over such a long time,” Anglada-Escude said.

    “This discovery is very exciting,” said Professor Richard Nelson, Head of the Astronomy Unit at QMUL, who didn’t participate in the research. “It suggests that many potentially habitable worlds will be found in the next years around nearby stars by ground-based and space-based observatories, such as PLATO. Until we have detected a larger number of them, the properties and possible habitability of the near-most planetary systems will remain mysterious.”

    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 spectroscopy and world-leading laser guide star adaptive optics systems.

    HIRES (the High-Resolution Echelle Spectrometer) produces spectra of single objects at very high spectral resolution, yet covering a wide wavelength range. It does this by separating the light into many “stripes” of spectra stacked across a mosaic of three large CCD detectors. HIRES is famous for finding planets orbiting other stars. Astronomers also use HIRES to study distant galaxies and quasars, finding clues to the Big Bang.

    Keck Eschellette Spectrograph
    High-Resolution Echelle Spectrometer

    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.
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  • richardmitnick 1:53 pm on April 17, 2014 Permalink | Reply
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    From Keck: “First Potentially Habitable Earth-Sized Planet Confirmed by Keck and Gemini Observatories” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    April 17, 2014
    Media Contact:
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    sjefferson@keck.hawaii.edu
    (808) 881-3827 (Desk)
    (808) 345-1319 (Cell)

    Science Contacts:
    Elisa Quintana
    SETI Institute
    elisa.quintana@nasa.gov
    650-604-2467 (Desk)
    415-730-1724 (Cell)

    Steve Howell
    Project Scientist, Kepler Mission
    NASA Ames Research Center, Moffett Field, CA
    steve.b.howell@nasa.gov
    (650) 604-4238 (Desk)(520) 461-6925 (Cell)

    The first Earth-sized exoplanet orbiting within the habitable zone of another star has been confirmed by observations with both the W. M. Keck Observatory and the Gemini Observatory. The initial discovery, made by the Kepler Space Telescope, is one of a handful of smaller planets found by Kepler and verified using large ground-based telescopes.

    NOAO Gemini North
    NOAO Gemini North Telescope

    NASA Kepler Telescope
    NASA/Kepler

    “What makes this finding particularly compelling is that this Earth-sized planet, one of five orbiting this star, which is cooler than the Sun, resides in a temperate region where water could exist in liquid form,” says Elisa Quintana of the SETI Institute and NASA Ames Research Center who led the paper published in the current issue of the journal Science. The region in which this planet orbits its star is called the habitable zone, as it is thought that life would most likely form on planets with liquid water.

    Steve Howell, Kepler’s Project Scientist and a co-author on the paper, adds that neither Kepler (nor any telescope) is currently able to directly spot an exoplanet of this size and proximity to its host star. “However, what we can do is eliminate essentially all other possibilities so that the validity of these planets is really the only viable option.”

    With such a small host star, the team employed a technique that eliminated the possibility that either a background star or a stellar companion could be mimicking what Kepler detected. To do this, the team obtained extremely high spatial resolution observations from the eight-meter Gemini North telescope on Mauna Kea in Hawai`i using a technique called speckle imaging, as well as adaptive optics (AO) observations from the ten-meter Keck II telescope, Gemini’s neighbor on Mauna Kea. Together, these data allowed the team to rule out sources close enough to the star’s line-of-sight to confound the Kepler evidence, and conclude that Kepler’s detected signal has to be from a small planet transiting its host star.

    “The Keck and Gemini data are two key pieces of this puzzle,” says Quintana. “Without these complementary observations we wouldn’t have been able to confirm this Earth-sized planet.”

    The Gemini “speckle” data directly imaged the system to within about 400 million miles (about 4 AU, approximately equal to the orbit of Jupiter in our solar system) of the host star and confirmed that there were no other stellar size objects orbiting within this radius from the star. Augmenting this, the Keck AO observations probed a larger region around the star but to fainter limits. According to Quintana, “These Earth-sized planets are extremely hard to detect and confirm, and now that we’ve found one, we want to search for more. Gemini and Keck will no doubt play a large role in these endeavors.”

    The planet designated Kepler-186f is earth-sized and orbits within the star’s habitable zone. The host star, Kepler-186, is an M1-type dwarf star relatively close to our solar system, at about 500 light years and is in the constellation of Cygnus. The star is very dim, being over half a million times fainter than the faintest stars we can see with the naked eye. Five small planets have been found orbiting this star, four of which are in very short-period orbits and are very hot.

    The Kepler evidence for this planetary system comes from the detection of planetary transits. These transits can be thought of as tiny eclipses of the host star by a planet (or planets) as seen from the Earth. When such planets block part of the star’s light, its total brightness diminishes. Kepler detects that as a variation in the star’s total light output and evidence for planets. So far more than 2,500 possible planets have been detected by this technique with Kepler.

    The Gemini data utilized the Differential Speckle Survey Instrument (DSSI) on the Gemini North telescope. DSSI is a visiting instrument developed by a team led by Howell who adds, “DSSI on Gemini Rocks! With this combination, we can probe down into this star system to a distance of about 4 times that between the Earth and the Sun. It’s simply remarkable that we can look inside other solar systems.” DSSI works on a principle that utilizes multiple short exposures of an object to capture and remove the noise introduced by atmospheric turbulence producing images with extreme detail.

    “The observations from Keck and Gemini, combined with other data and numerical calculations, allowed us to be 99.98% confident that Kepler-186f is real,” says Thomas Barclay, a Kepler scientist and also a co-author on the paper. “Kepler started this story, and Gemini and Keck helped close it,” adds Barclay.

    Observations with the W.M. Keck Observatory used the Natural Guide Star Adaptive Optics system with the NIRC2 camera on the Keck II telescope. 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.

    [I was unable to find graphic of Differential Speckle Survey Instrument (DSSI), or NIRC2 (the Near-Infrared Camera, second generation)

    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.
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  • richardmitnick 7:12 pm on April 2, 2014 Permalink | Reply
    Tags: , , , , Keck Observatory   

    From Keck: “Aussie Scientist Finds Rare Supernova at Keck Observatory” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    April 2, 2014
    By Prof. Duncan Forbes, professor of astronomy at Swinburne University in Melbourne, Australia

    It was a clear night on the summit of Mauna Kea at Keck Observatory on the 20th March. My colleagues and I were using the Echellette Spectrograph and Imager (ESI) instrument, which looks at faint objects in the visible wavelengths, to study star clusters and small galaxies.

    Keck Eschellette Spectrograph
    Echellette Spectrograph and Imager (ESI)

    I was actually in our special ‘remote ops’ room at Swinburne University, with my postdoc, Joachim Janz. This is a room decked out with a computer, a backup computer, a video-link to Keck Observatory and a dedicated Internet connection. As we are 21 hours ahead of Hawaii, it was a Friday afternoon when we started observing that Thursday night. My colleagues Sam Penny and Mark Norris were in the Keck control room, and Aaron Romanowsky was in his remote ops room at UC Santa Cruz.

    Shortly into our night’s observing, we noticed a bright source in the guide camera image that wasn’t on our finding chart of that region. Still we managed to find our target and took a spectrum of it. But we decided to go back and see if that `new’ bright source was still there. Sure enough it was and it hadn’t moved. It was probably a supernova (or an asteroid coming straight at us!), so I decided to get a 5min spectrum with ESI. And indeed we had found a supernova—a type Ia to be exact. Type Ia supernovae are fairly rare in the nearby Universe and represent the explosion of at least one white dwarf star in a binary system. It is this same type of supernova that led to the discovery of Dark Energy in the Universe using the Keck Observatory, and three Nobel prizes.

    Our supernova is located in the outskirts of a galaxy some 100 million light years from us—so it exploded 100 million years ago but the light only reached us that night.

    I later found out that an automated telescope on the Palomar Mountain overlooking Los Angeles detected the supernova shortly before us. They also managed to get a spectrum but that was taken after our Keck II/ESI spectrum. The exciting thing is that both the Palomar Observatory and ourselves managed to observe the supernova in the 1-2 weeks before it reaches its maximum brightness (and then fades steadily after that).

    Caltech Palomar Observatory
    Palomar

    The supernova has been given the designation SN2014ai.

    All in all, not bad for a late night at the office…

    See the full article here.

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

    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.
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  • richardmitnick 3:20 pm on February 27, 2014 Permalink | Reply
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    From Keck: “Distant Asteroid Revealed to be a Complex Mini Geological World” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    February 27, 2014
    Media Contact:
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    (808)881-3827
    sjefferson@keck.hawaii.edu

    After 8 years of observations scientists from the SETI Institute have found an exotic orbit for the largest Trojan asteroid, (624) Hektor—the only one known to possess a moon. The formation of this system made of a dual primary and a small moon is still a mystery, but they found the asteroid could be a captured Kuiper body product of the reshuffling of giant planets in our solar system. The results are being published today in Astrophysical Journal Letters.

    object
    Two adaptive optics observations made in July 2006 and October 2008 with the Keck II telescope. The center of each image shows the elongated shape of Hektor. The small, faint moon is shown in the cyan circle.

    This study, based on W. M. Keck Observatory data and photometric observations from telescopes throughout the world, suggests that the asteroid and its moon are products of the collision of two icy asteroids. This work sheds light on the complex youth of our solar system, when the building blocks that formed the core of giant planets and their satellites were tossed around or captured during the giant planet migrations.

    In 2006, a small team of astronomers led by Franck Marchis, astronomer at the Carl Sagan center of the SETI Institute, detected the presence of a small 12 km diameter moon around the large Trojan asteroid (624) Hektor. They used the 10 m Keck II telescope atop Mauna Kea, fitted with the NIRC-2 (the Near-Infrared Camera 2) instrument behind the adaptive optics and laser guide star system (LGS-AO).

    Since then, they collaborated with several researchers from University of California at Berkeley to determine the orbit of this moon and understand the origin of the system. Trojan asteroids are those that are temporarily trapped in regions 60 degrees in front of or 60 degrees behind the planet Jupiter in its orbit around the Sun. They are difficult to study since they are small and faint.

    While the asteroid has been studied for 8 years, there were a couple of significant challenges before a paper could be published, according to Marchis. “The major one was technical: the satellite can be seen only with a telescope like Keck Observatory’s fitted with LGS-AO, but time on the mighty Keck’s is highly prized and in limited availability,” he said. “Secondly, the orbit of the satellite is so bizarre that we had to develop a complex new algorithm to be able to pin it down and understand its stability over time.”

    The research, conducted with expert assistance from colleagues at the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) of the Observatoire de Paris, revealed that the 12 km moon orbits the large 250 km asteroid every 3 days at a distance of 600 km in an ellipse inclined almost 45 degrees with respect to the asteroid’s equator.

    “The orbit of the moon is elliptical and tilted relative to the spin of Hektor, which is very different from other asteroids with satellites seen in the main-belt,” said Matija Cuk, coauthor and scientist at the Carl Sagan Center of the SETI Institute. “However, we did computer simulations, which include Hektor being a spinning football shape asteroid and orbiting the Sun, and we found that the moon’s orbit is stable over billions of years.”

    Hektor has been known since the 1970s to be spinning rapidly (less than 7 hours) and extremely elongated. Using the high angular resolution of the Keck II telescope, combined with a large number of photometric observations taken since 1957, the team built a refined shape hoping to get a clue to the origin of the system.

    “We built several models of equal quality from the photometric data, but we favored a model made of two lobes since some of the best adaptive optics observations suggest that the Trojan asteroid has a dual structure,” said Josef Durech, co-author and researcher at the Charles University in Prague.

    A complex shape for the asteroid and a bizarre orbit for the moon will be matters of discussion for the scientific community. The team speculated that the moon could be ejecta produced by a slow encounter that formed the bi-lobed asteroid, but emphasized the need for robust and accurate simulations.

    “We also show that Hektor could be made of a mixture of rock and ices, similar to the composition of Kuiper belt objects, Triton and Pluto. How Hektor became a Trojan asteroid, located at only 5 times the Earth–Sun distance, is probably related to the large scale reshuffling that occurred when the giant planets were still migrating,” said Julie Castillo-Rogez, researcher at the Jet Propulsion Laboratory, California Institute of Technology.

    Hektor was discovered in 1907 by August Kopff. The satellite of Hektor, discovered in 2006 by Franck Marchis and his team has not been named yet. The team welcomes any idea for naming the satellite, keeping in mind that the satellite should receive a name closely related to the name of the primary and reflecting the relative sizes between these objects.

    The paper entitled The puzzling mutual orbit of the binary Trojan asteroid (624) Hektor published today by ApJL is co-authored by F. Marchis (SETI Institute), J. Durech (Charles University), J. Castillo-Rogez (Jet Propulsion Laboratory), F. Vachier (IMCCE-Obs. De Paris), M. Cuk (SETI Institute), J. Berthier (IMCCE-Obs. De Paris), M.H. Wong (UC Berkeley), P. Kalas (UC Berkeley), G. Duchene (UC Berkeley), M. A. van Dam (Flat Wavefronts), H. Hamanowa (Hamanowa observatory)and M. Viikinkoski (Tampere University)

    The mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe. The SETI Institute is a private, nonprofit organization dedicated to scientific research, education and public outreach. Founded in November 1984, the SETI Institute began operations on February 1, 1985.

    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 spectroscopy and world-leading laser guide star adaptive optics systems.

    NIRC-2 (the Near-Infrared Camera 2) is a versatile instrument specifically built for use with the Keck II adaptive optics system. It has three cameras, with different scales and fields of view, from 10 milliarcsec pixels and a 10 arc second field of view to a 40 milliarcsec/40 arcsec field of view. It is used predominantly for imaging, although it also has grisms for spectroscopy. NIRC-2 plays a major role in research on the Galactic Center and the black hole that resides there, as well as the cores of other galaxies, binary stars and binary asteroids, and the surfaces of Solar System bodies.

    See the full article here.

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

    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.
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  • richardmitnick 5:50 pm on February 13, 2014 Permalink | Reply
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    From Keck: “Serendipitous Supernova” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    February 13, 2014
    Steve Jefferson

    Two weeks ago a group of astronomy students from the University of London Observatory were getting an introductory demonstration on how to use a telescope-mounted camera. With clouds shrouding much of the sky, professor Steve Fossey decided to point the University’s 14-inch telescope at nearby galaxy Messier 82 (M82) and saw a very bright object that wasn’t supposed to be there. After a bit of detective work, the group put out an Astronomical Telegram to the world’s scientific community.

    m82
    A mosaic image taken by the Hubble Telescope of Messier 82, combining exposures taken with four colored filters that capture starlight from visible and infrared wavelengths as well as the light from the glowing hydrogen filaments.

    It was soon determined that M82 was hosting a rare, Type 1a supernova explosion – one of the brightest events in the sky and a once-in-a-century event. It was named SN2014J.

    sn2014j
    First image: Messier 82 on 10 December 2013. Second image: The same view on 22 January 2014. The position of the supernova is marked.
    Discovery date 21 January 2014 University of London Observatory

    The phones rang at Keck Observatory, home of the two largest and most scientifically productive telescopes on the Earth. Although time on the Keck telescopes is scheduled 6 months in advance and is highly coveted, the two different teams observing on Keck I and Keck II that night both agreed to interrupt their research and point the mighty 10-meter telescopes at M82 and gather valuable data and rare insight into the life cycle of type 1a supernova.

    “It was very exciting: this was the second nearest supernova in recent history,” said Michael Liu, the University of Hawaii astronomer who made the decision to observe the exploding star using the Keck II telescope. “Usually, we know what we are going to be observing for months before we get here.”

    While it’s known that Type 1a supernovae form from collapsing white dwarfs – the densest forms of matter after black holes and neutron stars – their formation theories come in two flavors: the single degenerate scenario in which a normal star is consumed by a white dwarf; and the double degenerate scenario in which two white dwarfs merge.

    To determine which one this is, scientists need to compare the before and after images to determine which stars became the supernova, said Shriharsh Tendulkar, a post-doctoral researcher at the California Institute of Technology.

    “Keck‘s Adaptive Optics system allows you to get very sharp images of the sky, as you would from space, and allows a very precise position of the supernova,” he said. “We can compare it to old images to possibly determine the progenitor system.”

    With the NIRC2 instrument and Keck II’s Adaptive Optics system (AO), Liu’s team was able to capture very clear images of the supernova and the surrounding stars in Messier 82.

    “While there are many supernovae explosions in the Universe, this one is important because it is close enough that with Keck’s AO, we have an excellent chance of identifying the progenitor,” said Bob Goodrich, head of night-time operations for W. M. Keck Observatory

    Critically, the supernova was discovered two weeks before its predicted peak luminosity, allowing an unprecedented opportunity to study the process of this stellar explosion.

    sn
    An image of the area of M82 acquired from the Keck Observatory using the NIRC2 instrument and the Keck II Adaptive Optics (AO) system showing the supernova SN2014J. By accurately matching the NIRC2 image to an archival HST image, astronomers can infer properties of the progenitor star or progenitor system that led to the supernova, confirming or discarding different hypotheses. Keck Observatory’s AO systems allow astronomers to reduce the blurring effect of atmospheric turbulence and acquire images as sharp as observed from space.

    “The physics of supernovae is very interesting,” Shriharsh said. “For example, it’s really hard to model these explosions in [computer] simulations. These observations will help us make our simulations better.”

    Yale University astronomer Meg Urry also took time from her program on Keck I to gather data on M82 using the Observatory’s newest instrument, MOSFIRE, the Multi-Object Spectrograph for Infrared Exploration. She wrote about her perspective in an interesting article for CNN.

    “In addition to giving insight on how these supernovae are formed, gathering data on SN2014J will give us more accurate distances to other type 1a supernovae,” Goodrich said. “Because the distance of M82 is precisely known, we can clearly determine the absolute brightness of SN2014J. Since all type 1a supernovae are equally bright, this valuable measurement can be used to calibrate data on all former (and future) such studies, including the one that lead to the Nobel Prize.”

    Type 1a supernovae have already played a profound role at the Keck Observatory when a team of astronomers were awarded the 2011 Nobel Prize in Physics. The scientists trained the mighty Keck telescopes at known supernovae and used their findings to determine that the expansion of the Universe was not slowing down, as was expected, but in fact was speeding up – driven by a mysterious repelling force now called Dark Energy.

    See the full article here.

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

    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.
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  • richardmitnick 5:32 am on January 30, 2014 Permalink | Reply
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    From Keck: “Rare Brown Dwarf Discovery Provides Benchmark for Future Exoplanet Research” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    January 20, 2014
    Media Contact
    Steve Jefferson
    Communications Officer
    W. M. Keck Observatory
    (808)-881-3827
    sjefferson@keck.hawaii.edu

    Science Contact:
    Justin Crepp
    (574) 631-4092
    jcrepp@nd.edu

    A team of researchers led by Justin R. Crepp, the Freimann Assistant Professor of Physics at the University of Notre Dame, has directly imaged a very rare type of brown dwarf that can serve as a benchmark for studying objects with masses that lie between stars and planets. Their paper on the discovery was published recently in Astrophysical Journal.

    bd

    Initial data came from the TRENDS (TaRgetting bENchmark-objects with Doppler Spectroscopy) high-contrast imaging survey that uses adaptive optics and related technologies to target older, faint objects orbiting nearby stars, and precise measurements were made at the W. M. Keck Observatory on the summit of Mauna Kea, Hawaii. Brown dwarfs emit little light because they do not burn hydrogen and cool rapidly. Crepp said they could provide a link between our understanding of low-mass stars and smaller objects such as planets.

    HD 19467 B, a T-dwarf, is a very faint companion to a nearby Sun-like star, more than 100,000 times as dim as its host. Its distance is known precisely, and the discovery also enables researchers to place strong constraints on important factors such as its mass, orbit, age, and chemical composition without reference to the spectrum of light received from its surface.

    Precise radial velocity measurements were obtained using the HIRES instrument installed on Keck Observatory’s 10-meter, Keck I telescope. The observations, which span 17 years starting from 1996, show a long-term acceleration, indicating that a low-mass companion was “tugging” on the parent star. Follow-up high-contrast imaging observations were then taken in 2012 using the NIRC2 instrument on the Keck II telescope with the adaptive optics system revealing the companion as shown above. Observations were granted through each of the Keck Observatory consortium members, including NASA, the California Institute of Technology, and the University of California.

    hires
    Picture of HIRES MAGIQ guider optics

    nirc2
    NIRC2

    While scientists understand the light received from stars relatively well, the spectra from planets is complicated and little understood. Understanding brown dwarfs, such as HD 19467 B, could be a step towards a fuller understanding of exoplanets.

    “This object is old and cold and will ultimately garner much attention as one of the most well-studied and scrutinized brown dwarfs detected to date,” Crepp said. “With continued follow-up observations, we can use it as a laboratory to test theoretical atmospheric models. Eventually we want to directly image and acquire the spectrum of Earth-like planets. Then, from the spectrum, we should be able to tell what the planet is made out of, what its mass is, radius, age, etc., basically all relevant physical properties.”

    HIRES (the High-Resolution Echelle Spectrometer) produces spectra of single objects at very high spectral resolution, yet covering a wide wavelength range. It does this by separating the light into many “stripes” of spectra stacked across a mosaic of three large CCD detectors. HIRES is famous for finding planets orbiting other stars. Astronomers also use HIRES to study distant galaxies and quasars, finding clues to the Big Bang.

    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.

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

    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.
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