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  • richardmitnick 1:35 pm on October 24, 2014 Permalink | Reply
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    From Daily Californian: “Senate meets to support observatory, proposition, research campus” 

    Daily Californian

    The Daily Californian

    October 24, 2014
    Heyun Jeong

    The ASUC Senate passed bills supporting the preservation of Lick Observatory, a state proposition and a new research campus on Wednesday evening.

    UCO Lick Observatory
    Lick Observatory

    Adopted with unanimous consent, the bills establish the ASUC’s support for the different issues and order executives to write up letters or public statements on behalf of the ASUC.

    In response to talks of terminating UC funding for Lick Observatory by 2018, CalSERVE Senator Lavanya Jawaharlal sponsored SB 25 to show support in continuing the observatory’s operations. The bill establishes a committee of students to raise awareness and propose alternative funding options and urges the UC Office of the President to recommit funds.

    The talks of disinvestment make it “difficult to get outside funding, when private donors are wondering why they should invest money when the UC is cutting funding,” Jawaharlal said.

    The committee, which will be made up of two senators and five appointed students, will work on increasing communication with the campus administration and raising student awareness not only on the UC Berkeley campus, but also across the entire UC system.

    “It’s a UC-system owned observatory and not just Berkeley,” she said. “It affects all campuses. … It’s important to raise student awareness and mobilize all of the UC system students.”

    According to Jawaharlal, the ASUC is the first student government to pass such a bill or create a special committee for the observatory.

    The senate also passed a bill in support of Proposition 47, which would reclassify certain crimes to misdemeanors instead of felonies.

    Sponsored by CalSERVE Senator Yordanos Dejen, the bill states that the proposition “will ensure that prison spending is focused on violent and serious offenses and will maximize alternatives for non-serious, nonviolent crime.”

    The senate also showed support for plans of a research campus to be built in Richmond.

    The Richmond Bay Campus, which will be developed in phases over the next 40 years, will provide additional research facilities for both UC Berkeley and the Lawrence Berkeley National Laboratory. By having the second campus in Richmond, bill sponsor and CalSERVE Senator Austin Pritzkat said he envisions that the campus will provide a much-needed revitalization of the economy for the surrounding neighborhood.

    Finance officer Dennis Lee was also confirmed as one of the two undergraduate representatives to the Student Union Board. He will replace Arushi Saxena and serve for the rest of the year with Ismael Contreras.

    Lee said he hopes to increase transparency by connecting the Student Union and the ASUC as the board focuses on overseeing commercial activities concerning the new Student Union, set to open next fall.

    See the full article here.

    The Daily Californian is an independent, student-run newspaper published by the Independent Berkeley Students Publishing Company, Inc. The newspaper serves the UC Berkeley campus and its surrounding community, publishing Monday through Friday during the academic year and twice a week during the summer. Established in 1871, The Daily Californian is one of the oldest newspapers on the West Coast and one of the oldest college newspapers in the country. Daily Cal staffers have the unique opportunity of gaining daily metro news experience in the lively city of Berkeley. The newspaper has consistently covered the city and its institutions since its establishment, allowing student journalists to report on campus as well as city news. The Daily Cal also operates Best of Berkeley, a city guide and local arts Web site for the city of Berkeley.

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  • richardmitnick 12:00 pm on October 24, 2014 Permalink | Reply
    Tags: , Charles Munger, , ,   

    From NYT: “Charles Munger, Warren Buffett’s Longtime Business Partner, Makes $65 Million Gift” 

    New York Times

    The New York Times

    October 24, 2014
    Michael J. de la Merced

    Charles T. Munger has been known for many things over his decades-long career, including longtime business partner of Warren E. Buffett; successful investor and lawyer; and plain-spoken commentator with a wide following.

    cm

    Now Mr. Munger, 90, can add another title to that list: deep-pocketed benefactor to the field of theoretical physics.

    He was expected to announce on Friday that he has donated $65 million to the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara. The gift — the largest in the school’s history — will go toward building a 61-bed residence for visitors to the institute, which brings together physicists for weeks at a time to exchange ideas.

    “U.C.S.B. has by far the most important program for visiting physicists in the world,” Mr. Munger said in a telephone interview. “Leading physicists routinely are coming to the school to talk to one another, create new stuff, cross-fertilize ideas.”

    ucsb
    UC Santa Barbara Campus

    The donation is the latest gift by Mr. Munger, a billionaire who has not been shy in giving away the wealth he has accumulated as vice chairman of Mr. Buffett’s Berkshire Hathaway to charitable causes.

    Though perhaps not as prominent a donor as his business partner, who cocreated the Giving Pledge campaign for the world’s richest people to commit their wealth to philanthropy, Mr. Munger has frequently donated big sums to schools like Stanford and the Harvard-Westlake School. (He has not signed on to the Giving Pledge campaign.)

    The biggest beneficiary of his largess thus far has been the University of Michigan, his alma mater. Last year alone, he gave $110 million worth of Berkshire shares — one of the biggest gifts in the university’s history — to create a new residence intended to help graduate students from different areas of study mingle and share ideas.

    That same idea of intellectual cross-pollination underpins the Kavli Institute, which over 35 years has established itself as a haven for theoretical physicists from around the world to meet and discuss potential new developments in their field.

    Funded primarily by the National Science Foundation, the institute has produced advances in the understanding of white dwarf stars, string theory and quantum computing.

    A former director of the institute, David J. Gross, shared in the 2004 Nobel Prize in Physics for work that shed new light on the fundamental force that binds together the atomic nucleus.

    “Away from day-to-day responsibilities, they are in a different mental state,” Lars Bildsten, the institute’s current director, said of the center’s visitors. “They’re more willing to wander intellectually.”

    To Mr. Munger, such interactions are crucial for the advancement of physics. He cited international conferences attended by the likes of [Albert]Einstein and Marie Curie.

    Mr. Munger himself did not study physics for very long, having taken a class at the California Institute of Technology while in the Army during World War II. But as an avid reader of scientific biography, he came to appreciate the importance of the field.

    And he praised the rise of the University of California, Santa Barbara, as a leading haven for physics, particularly given its status as a relatively young research institution.

    But while the Kavli Institute conducts various programs throughout the year for visiting scientists, it has long lacked a way for physicists to spend time outside of work hours during their stays. A permanent residence hall would allow them to mingle even more, in the hope of fostering additional eureka moments.

    “We want to make their hardest choice, ‘Which barbecue to go to?’ ” Mr. Bildsten joked.

    Though Mr. Munger has some ties to the University of California, Santa Barbara — a grandson is an alumnus — he was first introduced to the Kavli Institute through a friend who lives in Santa Barbara.

    During one of the pair’s numerous fishing trips, that friend, Glen Mitchel, asked the Berkshire vice chairman to help finance construction of a new residence. The university had already reserved a plot of land for the dormitory in case the institute raised the requisite funds.

    “It wasn’t a hard sell,” Mr. Munger said.

    “Physics is vitally important,” he added. “Everyone knows that.”

    See the full article here.

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  • richardmitnick 11:04 am on October 24, 2014 Permalink | Reply
    Tags: , , , , , ,   

    From CfA: “Accreting Supermassive Black Holes in the Early Universe” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    October 24, 2014
    No Writer Credit

    Supermassive black holes containing millions or even billions of solar-masses of material are found at the nuclei of galaxies. Our Milky Way, for example, has a nucleus with a black hole with about four million solar masses of material. Around the black hole, according to theories, is a torus of dust and gas, and when material falls toward the black hole (a process called accretion) the inner edge of the disk can be heated to millions of degrees. Such accretion heating can power dramatic phenomena like bipolar jets of rapidly moving charged particles. Such actively accreting supermassive black holes in galaxies are called active galactic nuclei (AGN).

    torus
    Torus

    The evolution of AGN in cosmic time provides a picture of their role in the formation and co-evolution of galaxies. Recently, for example, there has been some evidence that AGN with more modest luminosities and accretion rates (compared to the most dramatic cases) developed later in cosmic history (dubbed “downsizing”), although the reasons for and implications of this effect are debated. CfA astronomers Eleni Kalfontzou, Francesca Civano, Martin Elvis and Paul Green and a colleague have just published the largest study of X-ray selected AGN in the universe from the time when it was only 2.5 billion years old, with the most distant AGN in their sample dating from when the universe was about 1.2 billion years old.

    The astronomers studied 209 AGN detected with the Chandra X-ray Observatory.

    NASA Chandra Telescope
    NASA/Chandra

    image
    A multicolor image of galaxies in the field of the Chandra Cosmic Evolution Survey. A large, new study of 209 galaxies in the early universe with X-ray bright supermassive black holes finds that more modest AGN tend to peak later in cosmic history, and that obscured and unobscured AGN evolve in similar ways.
    X-ray: NASA/CXC/SAO/F.Civano et al. Optical: NASA/STScI

    They note that the X-ray observations are less contaminated by host galaxy emission than optical surveys, and consequently that they span a wider, more representative range of physical conditions. The team’s analysis confirms the proposed trend towards downsizing, while it also can effectively rule out some alternative proposals. The scientists also find, among other things, that this sample of AGN represents nuclei with a wide range of molecular gas and dust extinction. Combined with the range of AGN dates, this result enables them to conclude that obscured and unobscured phases of AGN evolve in similar ways.

    See the full article here.

    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

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  • richardmitnick 10:43 am on October 24, 2014 Permalink | Reply
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    From astrobio.net: “The Abundance of Water in Asteroid Fragments” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 24, 2014
    Aaron L. Gronstal

    A new study could provide insights about the abundance of water in fragments from a famous asteroid.

    two
    These colorful images are of thin slices of meteorites viewed through a polarizing microscope. Part of the group classified as HED meteorites for their mineral content (Howardite, Eucrite, Diogenite), they likely fell to Earth from 4 Vesta. Credit: NASA / JPL-Caltech / Hap McSween (Univ. Tennessee), A. Beck and T. McCoy (Smithsonian Inst.)

    The study focused on a mineral called apatite, which can act as a record of the volatiles in materials, including things like magma and lunar rocks. Volatiles are chemical elements with low boiling points (like water), and are usually associated with a celestial bodies’ crust or atmosphere.

    By looking at the apatite in meteorites, the team was able to determine the history of water in these rocks from space.

    The meteorites they chose to study are known as the Howardite-Eucrite-Diogenite (HED) meteorites. These meteorites are a subset of the achondrite meteorites, which are stony meteorites that do not have any chondrites (round grains that were formed from molten droplets of material floating around in space before being incorporated into an asteroid).

    vesta
    Vesta closeup. Credit: NASA

    Studying the composition of meteorites can provide important clues about how asteroids and other rocky bodies form and evolve. Volatile elements influence processes important to planet formation, such as melting and eruption processes.

    HED meteorites are especially interesting because scientists think they originated from the crust of the asteroid Vesta – a large body in the main asteroid belt that was recently visited by NASA’s Dawn spacecraft. Behind Ceres, Vesta is the second largest object in the asteroid belt and is sometimes referred to as a protoplanet.

    Vesta is a relic of the ancient Solar System and can help astrobiologists understand our system’s formation and evolution. This information provides clues about conditions in the Solar System that led to the formation of a habitable planet – the Earth.

    Interestingly, the team’s results from the HED meteorites are similar to studies on the Earth and Moon, and could support theories that water in all three objects (Vesta, the Earth, and the Moon) came from the same source.

    See the full article here.

    NASA

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  • richardmitnick 9:42 am on October 24, 2014 Permalink | Reply
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    From SPACE.com: “Einstein’s Gravity Waves Could Be Found with New Method” 

    space-dot-com logo

    SPACE.com

    October 24, 2014
    Charles Q. Choi

    Gravitational waves, invisible ripples in the fabric of space and time, might be detected by looking for the brightening of stars, researchers say.

    gw
    This illustration depicts the gravitational waves generated by two black holes orbiting each other.
    Credit: NASA

    These mysterious ripples were first proposed by Albert Einstein as part of his theory of general relativity. The waves’ size depends on the mass of the objects creating them.

    “Gravitational waves are emitted by accelerating masses,” said lead study author Barry McKernan, an astrophysicist at the American Museum of Natural History in New York. Really big waves are emitted by really big masses, such as systems containing black holes merging with each other.

    Scientists have still not made direct observations of gravitational waves, although researchers continue to endeavor to detect them using experiments involving lasers on the ground and in space. The waves interact very weakly with matter, which partly explains why seeing these ripples in spacetime is difficult.

    Now, McKernan and his colleagues suggest that gravitational waves could have more of an effect on matter than previously thought, with their influence potentially brightening stars.

    “It’s neat that nearly 100 years after Einstein proposed his theory of general relativity, there are still interesting surprises it can turn up,” McKernan told Space.com. “We’re brought up as astronomers thinking the interaction between matter and gravitational waves is very weak, essentially negligible, and that turns out not to be true.”

    The researchers suggest that stars that vibrate at the same frequency as gravitational waves passing through them can absorb a large amount of energy from the ripples.

    “You can imagine gravitational waves as sounds from a piano, and stars as a vibrating violin string held near that piano,” McKernan said. “If the frequency of the sounds matches the frequency of the violin string, the string can resonate with the sound.” If a star gets pumped up with large amounts of energy from gravitational waves in this way, “the star can puff up and look brighter than it normally would,” McKernan said.

    One challenge is determining whether any star brightening astronomers detect is from gravitational waves or some other factor. The researchers suggest the key to spotting the effects of gravitational waves involves looking at large groups of stars.

    “When a population of stars is near a system of merging black holes and is getting pounded by gravitational waves, we think that the more massive stars will light up first,” McKernan said. “It’s like playing keys on a piano and starting with low pitches.” As the black holes get closer together, the frequency of the gravitational waves they generate will increase, “and we’d expect to see brightening of smaller stars,” he added. “If we see a population of stars where the smaller stars are brightening after the bigger stars in a collective way, that might be a sign of gravitational waves.”

    This research also suggests a different way to indirectly detect gravitational waves. If scientists develop working gravitational wave detectors on Earth or in space, when a star passes in front of powerful sources of gravitational waves such as merging black holes, the detector may see a drop in the intensity of those waves. This will happen if the eclipsing star is vibrating at the right frequency.

    “You usually think of stars as being eclipsed by something, not the other way around,” McKernan said in a statement.

    McKernan and his colleagues Saavik Ford, Bence Kocsis and Zoltan Haiman detailed their findings online Sept. 22 in the journal Monthly Notices of the Royal Astronomical Society: Letters.

    See the full article here.

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  • richardmitnick 9:20 am on October 24, 2014 Permalink | Reply
    Tags: , , , , , , POLARBEAR Collaboration   

    From phys.org: “POLARBEAR detects curls in the universe’s oldest light” 

    physdotorg
    phys.org

    Oct 21, 2014
    Susan Brown

    Cosmologists have made the most sensitive and precise measurements yet of the polarization of the cosmic microwave background.

    image

    The report, published October 20 in the Astrophysical Journal, marks an early success for POLARBEAR, a collaboration of more than 70 scientists using a telescope high in Chile’s Atacama desert designed to capture the universe’s oldest light.

    “It’s a really important milestone,” said Kam Arnold, the corresponding author of the report who has been working on the instrument for a decade. “We’re in a new regime of more powerful, precision cosmology.” Arnold is a research scientist at UC San Diego’s Center for Astrophysics and Space Sciences and part of the cosmology group led by physics professor Brian Keating.

    POLARBEAR measures remnant radiation from the Big Bang, which has cooled and stretched with the expansion of the universe to microwave lengths. This cosmic microwave background, the CMB, acts as an enormous backlight, illuminating the large-scale structure of the universe and carrying an imprint of cosmic history.

    Cosmic Background Radiation Planck
    CMB from Planck

    Arnold and many others have developed sensitive instruments called bolometers to measure this light. Arrayed in the telescope, the bolometers record the direction of the light’s electrical field from multiple points in the sky.

    “It’s a map of all these little directions that the light’s electric field is pointing,” Arnold explained.

    POLARBEAR has now mapped these angles with resolution on a scale of about 3 arcminutes, just one-tenth the diameter of the full moon..

    The team found telling twists called B-Modes in the patterns of polarization, signs that this cosmic backlight has been warped by intervening structures in the universe, including such mysteries as dark matter, composed of substance that remains unknown, and the famously aloof particles called neutrinos, which elude capture making them difficult to study.

    This initial report, the result of the first season of observation, maps B-modes in three small patches of sky.

    Dust in our own galaxy also emits polarized radiation like the CMB and has influenced other measurements. But these patches are relatively clean, Arnold says. And variations in the CMB polarization due to dust occur on so broad a scale that they do not significantly influence the finer resolution B-modes in this report.

    “We are confident that these B-modes are cosmological rather than galactic in origin,” Arnold said.

    Observations continue, and the data stream will ultimately be fed by additional telescopes comprising the Simons Array. Together they will map wider swaths of the sky, making fundamental discoveries possible.

    Simmons Array

    “POLARBEAR is a real tour de force. With a relatively small, but strong, UC-led team we have surpassed the next-nearest competitors by an order of magnitude in sensitivity. We have paved the way towards solving the deepest mysteries in the quest to understand matter and energy at the beginning of time,” said Brian Keating.

    POLARBEAR is a collaboration of scientists from many institutions including experiment founder, Adrian Lee, professor of physics at UC Berkeley.

    See the full article here.

    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

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  • richardmitnick 8:17 am on October 24, 2014 Permalink | Reply
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    From SPACE.com:”Saturn’s ‘Death Star’ Moon Mimas Is Weird Inside” 

    space-dot-com logo

    SPACE.com

    October 16, 2014
    Kelly Dickerson

    There’s something strange going on below the surface of Saturn’s Death Star-looking moon Mimas, a new study suggests.

    star

    Mimas’ rotation and its orbit around Saturn make the moon look like it’s rocking and back forth and oscillating similar to the way a pendulum swings. The rocking motion is called libration, and it’s commonly observed in moons that are influenced by the gravity from neighboring planets. However, using images of the moon captured by the Cassini spacecraft, Radwan Tajeddine, a research associate at Cornell University, discovered that the satellite’s libration was much more exaggerated in one spot than predicted. He expects it must be caused by the moon’s weird interior.

    NASA Cassini Spacecraft
    NASA/ Cassini

    “We’re very excited about this measurement because it may indicate much about the satellite’s insides,” Tajeddine said in a statement. “Nature is essentially allowing us to do the same thing that a child does when she shakes a wrapped gift in hopes of figuring out what’s hidden inside.”

    Feel the libration

    Astronomers have long been using the rotation and orbit of celestial bodies to guess what their interiors might be like. Most of the rocking is explained by the interacting forces from Mimas’ rotation and orbit, but one libration was much larger than expected.

    Tajeddine and the team tested five different models of what Mimas might look like below the surface to see which one could explain the exaggerated rocking. They quickly ruled out the possibility that Mimas has a uniform interior, an interior with two different layers or an abnormal mass under the moon’s 88-mile-long (142 kilometers) crater that makes it look like the Death Star from the “Star Wars” franchise.

    However, the last two models could both explain Mimas’ extreme libration. One idea is that the moon has an elongated, oval-shaped core. This elongation might have happened as the moon formed under the push and pull of Saturn’s rings. The teeter tottering could also come from a subsurface ocean, similar to the one on Jupiter’s moon Europa.

    While it’s still a possibility, Tajeddine thinks the subsurface ocean is an unlikely explanation. Astronomers have not observed any evidence of liquid water on Mimas, unlike some of Saturn’s other moons. The heat radiating from the core escapes through the moon’s ice-covered shell and would cause any subsurface ocean that existed to quickly freeze.

    3D Mimas map

    Mimas is the smallest and closest of Saturn’s main eight moons. Its giant crater covers almost one-third of the moon’s icy surface.

    For the past 10 years,the Cassini space probe has been collecting data on Mimas, Saturn and the ringed wonder’s other natural satellites. The Imaging Science Subsystem (ISS) onboard Cassini is a two-camera system that captures ultraviolet and infrared images of Saturn and its moons.

    Tajeddine and a team of researchers sifted through dozens of images captured by ISS and created a 3D map of the moon from the photos to study how Mimas spins and orbits Saturn.

    The new research was published this week in the journal Science.

    See the full article here.

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  • richardmitnick 8:01 am on October 24, 2014 Permalink | Reply
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    From SETI: “New Insights on the Origin of the triple asteroid system (87) Sylvia” 


    SETI Institute

    Oct 24, 2014
    Franck Marchis, Senior Research Scientist

    Combining observations from the world’s largest telescopes with those from smaller instruments used by amateur astronomers, a team of scientists has discovered that the large main-belt asteroid (87) Sylvia has a complex interior. This has been deduced by using the motions of the two moons orbiting the main asteroid as probes of the object’s density distribution. The complex structure is probably linked to the way the multiple system was formed.

    two
    Description Discovery of the two moons Romulus and Remus of the asteroid (87) Sylvia
    Date 24 January 2007
    Adaptive Optics observations of (87) Sylvia, showing its two satellites, Remus and Romulus

    The findings were announced last year at the 45th annual Division of Planetary Sciences meeting in Denver, Colorado and were published last month in the journal Icarus.

    The asteroid (87) Sylvia is the first known to have two moons. One moon was discovered in 2001, and the second was found in 2005 by a team led by Franck Marchis, senior research scientist at the Carl Sagan Center of the SETI Institute. Since then, the team has continued to make new observations of the system using 8 to 10 m-class telescopes, including those at the Keck Observatory, the European Southern Observatory, and Gemini North.

    Keck Observatory
    Keck Observatory Interior
    Keck

    ESO VLT Interferometer
    ESO VLT Interior
    ESO VLT

    Gemini North telescope
    Gemini North Interior
    Gemini North

    syl
    (credit: Danielle Futselaar/SETI Institute).
    An artist’s rendition of the triple system showing the large 270-km asteroid Sylvia surrounded by its two moons – Romulus and Remus – gives a pictorial representation of this intriguing triple system.

    The differentiated interior of the asteroid is shown in a cutaway diagram. The primary asteroid may have a dense, regularly-shaped core, surrounding by fluffy or fractured material. The outer moon, named Romulus, is known to be strongly elongated, possibly having two lobes, as suggested by a recently observed occultation recorded by amateur astronomers.

    “Combined observations from small and large telescopes provide a unique opportunity to understand the nature of this complex and enigmatic triple asteroid system,” Marchis said. “Thanks to the presence of these moons, we can constrain the density and interior structure of an asteroid, without the need for a spacecraft’s visit. Knowledge of the internal structure of asteroids is key to understanding how the planets of our solar system formed.”

    The article Physical and dynamical properties of the main belt triple Asteroid (87) Sylvia, published last month in Icarus, is co-authored by J. Berthier, F. Vachier, B. Carry from IMCCE-Obs de Paris, J. Durech from Charles University, Prague, and F. Marchis from the SETI Institute and Obs. de Paris.

    Reference
    Berthier, J., F. Vachier, F. Marchis, J. Ďurech, and B. Carry. 2014. Physical and Dynamical Properties of the Main Belt Triple Asteroid (87) Sylvia. Icarus 239 (September): 118–30. doi:10.1016/j.icarus.2014.05.046.

    Abstract
    We present the analysis of high angular resolution observations of the triple Asteroid (87) Sylvia collected with three 8-10 m class telescopes (Keck, VLT, Gemini North) and the Hubble Space Telescope. The moons’ mutual orbits were derived individually using a purely Keplerian model. We computed the position of Romulus, the outer moon of the system, at the epoch of a recent stellar occultation which was successfully observed at less than 15 km from our predicted position, within the uncertainty of our model. The occultation data revealed that the Moon, with a surface-area equivalent diameter Ds=23.1±0.7km, is strongly elongated (axes ratio of 2.7±0.32.7±0.3), significantly more than single asteroids of similar size in the main-belt. We concluded that its shape is probably affected by the tides from the primary. A new shape model of the primary was calculated combining adaptive-optics observations with this occultation and 40 archived light-curves recorded since 1978. The difference between the J2=0.024-0.009+0.016 derived from the 3-D shape model assuming an homogeneous distribution of mass for the volume equivalent diameter Dv=273±10km primary and the null J2 implied by the Keplerian orbits suggests a non-homogeneous mass distribution in the asteroid’s interior.

    See the full article here.

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  • richardmitnick 8:09 pm on October 23, 2014 Permalink | Reply
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    From Frontier Fields: “Recent Guide Star Loss with Abell 2744″ 

    Frontier Fields
    Frontier Fields

    May 30, 2014
    Patricia Royle – Frontier Fields Program Coordinator

    We have just experienced our first non-acquisition of a guide star during Frontier Fields observations. This occurred while in the midst of Abell 2744 observations.

    bel
    Abell 2744, nicknamed Pandora’s Cluster. The galaxies in the cluster make up less than five percent of its mass. The gas (around 20 percent) is so hot that it shines only in X-rays (coloured red in this image). The distribution of invisible dark matter (making up around 75 percent of the cluster’s mass) is coloured here in blue.

    Since HST is in constant motion, pointing is maintained by a set of three Fine Guidance Sensors (FGS) which find and lock on to a pair of guide stars, or a single guide star if pairs are not available. These guide stars are selected by software based on several criteria, including magnitude, relative position to other similar stars, position within the FGS “pickles” (Fields of View) and any pointing constraints on the observation such as ORIENT or POS TARGs within the Phase 2 program. Selected guide stars need to stay within the FGS pickles for the entire orbit, including all pointing changes due to POS TARGs or PATTERNs. If an observation spans more than one visibility interval, the guide stars are reacquired after each interruption either from occultation or SAA passages. A pair of guide stars provides the most accurate and stable pointing since they act as sort of handles for HST to focus on. If two stars are used in two separate FGS pickles, then HST is able to maintain almost perfect pointing throughout the observations. If only one star is used, HST may show some drift around the single star since there is not a second star to keep the telescope from rotating. More information about the accuracy of each type of guiding can be found online at http://www.stsci.edu/hst/acs/faqs/guide_star.html.

    In some cases, a guide star may fail to acquire or it might successfully acquire but can not be maintained. Sometimes this is a result of a telescope problem, but more often, it turns out that a selected guide star fails to meet one of the criteria it initially appeared to pass. This can happen in the case of a variable star, a multi-star system that previously appeared as a single star, or with the presence of a similar star (called a spoiler) nearby that confuses the FGS. When PAIRs are used, it is possible to fail to acquire one star, but succeed with the other, resulting in observations taken with single star guiding which is often good enough for most science. There may also be situations when a star is acquired initially but fails to re-acquire in a subsequent orbit, or lock may be lost on one star during an orbit. This is usually due to the star itself being at the very edge of usability and violating one of the limits set by the telescope to help ensure HST knows where it is pointing. With guide star pairs, science can usually continue as long as one of the stars is acquired. If both stars fail (very unusual) or an observation using single star guiding fails to acquire its one star, the observations default to gyro control. This is often problematic to the science as the observations are likely to show significant drift and rotation, or may be far enough off that the target is completely missed.

    During the first Frontier Fields visit observing Abell 2744 on May 14, one of the two selected guide stars failed to acquire, resulting in the observations continuing on single star guiding instead. As with all failures, the failed star was investigated and was found to be a bad star. It was flagged in the database within 24 hours of the failure, such that future observations would not attempt to use the same bad star. The second Frontier Fields visit of Abell 2744 on May 15 also failed, as it was already on the telescope and set to use the same guide star pair. Several other visits that were scheduled to execute on the telescope the following week, with the same guide star pair, were quickly reworked by the calendar-building team at STScI to use a different guide star pair. The remaining visits in the epoch not yet put on a calendar are unaffected, since the bad star is no longer an option for our software when selecting from available guide star pairs.

    fs
    Figure 1: The HST Field of View of Abell 2744, with Fine Guidance Sensors Fields of View indicated by the large, gray arcs.

    The green boxes in Figure 1 identify potential guide stars. To use guide star pairs, two stars must fall into separate FGS pickles and remain there throughout any shifts in pointing during the visit. If two similar guide stars are too close to each other, neither can be used since the FGS could lock onto the wrong star. Because of the multiple criteria involved and the need for precision, not all guide stars can be used for a given observation, even if the Field of View seems to show stars that could be used.

    The Frontier Fields data products team carried out a detailed examination of all the data from the two visits that were affected by these guidestar issues. For the first visit (number 37), only one of the guidestars was lost, while the other star was successfully acquired and the observations were able to continue in single guide star mode. Analysis of the resulting images showed no measurable impact on the pointing or the PSF quality (consistent with our knowledge that HST is able to perform successfully with a single guide star, when necessary), and all the data from this visit were included in the mosaics.

    For the second visit (number 81), the failure mode was somewhat different. The guide stars were fine during the first two orbits of this 4-orbit visit, but began to show problems during the third orbit and failed the reacquisition for the fourth orbit. Consequently, the ACS shutter was closed at the start of the fourth orbit and the fourth exposure for each filter was not obtained. As a result, we include only the first two exposures for each filter in our fast-turnaround v0.5 products, although we may include the third exposure in future versions. For WFC3/IR, all the exposures were obtained, and analysis revealed that the last exposure was offset by no more than a few tenths of an arcsecond compared to its expected location. Thus, there was no significant evidence of drift during the exposures, indicating that the telescope was able to track successfully in gyro mode during these exposures.

    So, it makes no difference. Two, one, or zero guide stars – we can do great science in any case!

    See the full article here.

    Frontier Fields draws on the power of massive clusters of galaxies to unleash the full potential of the Hubble Space Telescope. The gravity of these clusters warps and magnifies the faint light of the distant galaxies behind them. Hubble captures the boosted light, revealing the farthest galaxies humanity has ever encountered, and giving us a glimpse of the cosmos to be unveiled by the James Webb Space Telescope.

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  • richardmitnick 7:38 pm on October 23, 2014 Permalink | Reply
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    From BNL: “National Synchrotron Light Source II Achieves ‘First Light'” 

    Brookhaven Lab

    October 23, 2014
    Chelsea Whyte, (631) 344-8671 or Peter Genzer, (631) 344-3174

    The National Synchrotron Light Source II detects its first photons, beginning a new phase of the facility’s operations. Scientific experiments at NSLS-II are expected to begin before the end of the year.

    crowd
    A crowd gathered on the experimental floor of the National Synchrotron Light Source II to witness “first light,” when the x-ray beam entered a beamline for the first time at the facility.

    The brightest synchrotron light source in the world has delivered its first x-ray beams. The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory achieved “first light” on October 23, 2014, when operators opened the shutter to begin commissioning the first experimental station (called a beamline), allowing powerful x-rays to travel to a phosphor detector and capture the facility’s first photons. While considerable work remains to realize the full potential of the new facility, first light counts as an important step on the road to facility commissioning.

    BNL NSLS II
    BNL NSLS-II Interior
    NSLS-II at BNL

    “This is a significant milestone for Brookhaven Lab, for the Department of Energy, and for the nation,” said Harriet Kung, DOE Associate Director of Science for Basic Energy Sciences. “The National Synchrotron Light Source II will foster new discoveries and create breakthroughs in crucial areas of national need, including energy security and the environment. This new U.S. user facility will advance the Department’s mission and play a leadership role in enabling and producing high-impact research for many years to come.”

    At 10:32 a.m. on October 23, a crowd of scientists, engineers, and technicians gathered around the Coherent Soft X-ray Scattering (CSX) beamline at NSLS-II, expectantly watching the video feed from inside a lead-lined hutch where the x-ray beam eventually struck the detector. As the x-rays hit the detector, cheers and applause rang out across the experimental hall for a milestone many years in the making.

    team
    The team of scientists, engineers, and technicians at the Coherent Soft X-ray Scattering (CSX) beamline gathered around the control station to watch as group leader Stuart Wilkins (seated, front) opened the shutter between the beamline and the storage ring, allowing x-rays to enter the first optical enclosure for the first time.

    “This achievement begins an exciting new chapter of synchrotron science at Brookhaven, building on the remarkable legacy of NSLS, and leading us in new directions we could not have imagined before,” said Laboratory Director Doon Gibbs. “It’s a great illustration of the ways that national labs continually evolve and grow to meet national needs, and it’s a wonderful time for all of us. Everyone at the Lab, in every role, supports our science, so we can all share in the sense of excitement and take pride in this accomplishment.”

    beam
    NSLS-II first x-rays
    Inside the beamline enclosure, a phosphor detector (the rectangle at right) captured the first x-rays (in white) which hit the mark dead center.

    In the heart of the 590,000 square foot facility, an electron gun emits packets of the negatively charged particles, which travel down a linear accelerator into a booster ring. There, the electrons are brought to nearly the speed of light, and then steered into the storage ring, where powerful magnets guide the beam on a half-mile circuit around the NSLS-II storage ring. As the electrons travel around the ring, they emit extremely intense x-rays, which are delivered and guided down beamlines into experimental end stations where scientists will carry out experiments for scientific research and discovery. NSLS-II accelerator operators have previously stored beam in the storage ring, but they hadn’t yet opened the shutters to allow x-ray light to reach a detector until today’s celebrated achievement.

    “We have been eagerly anticipating this culmination of nearly a decade of design, construction, and testing and the sustained effort and dedication of hundreds of individuals who made it possible,” said Steve Dierker, Associate Laboratory Director for Photon Sciences. ‘We have more work to do, but soon researchers from around the world will start using NSLS-II to advance their research on everything from new energy storage materials to developing new drugs to fight disease. I’m very much looking forward to the discoveries that NSLS-II will enable, and to the continuing legacy of groundbreaking synchrotron research at Brookhaven.”

    NSLS-II, a third-generation synchrotron light source, will be the newest and most advanced synchrotron facility in the world, enabling research not possible anywhere else. As a DOE Office of Science User Facility, it will offer researchers from academia, industry, and national laboratories new ways to study material properties and functions with nanoscale resolution and exquisite sensitivity by providing state-of-the-art capabilities for x-ray imaging, scattering, and spectroscopy.

    Currently 30 beamlines are under development to take advantage of the high brightness of the x-rays at NSLS-II. Commissioning of the first group of seven beamlines will begin in the coming months, with first experiments beginning at the CSX beamline before the end of 2014.

    At the NSLS-II beamlines, scientists will be able to generate images of the structure of materials such as lithium-ion batteries or biological proteins at the nanoscale level—research expected to advance many fields of science and impact people’s quality of life in the years to come.

    NSLS-II will support the Department of Energy’s scientific mission by providing the most advanced tools for discovery-class science in condensed matter and materials science, physics, chemistry, and biology—science that ultimately will enhance national and energy security and help drive abundant, safe, and clean energy technologies.

    Media Contacts:
    Karen McNulty Walsh, 631 344-8350 or kmcnulty@bnl.gov
    Chelsea Whyte, 631 344-8671 or cwhyte@bnl.gov

    See the full article here.

    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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