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  • richardmitnick 2:26 pm on October 11, 2018 Permalink | Reply
    Tags: , , , , , , , iPTF=intermediate Palomar Transient Factory, Massive star’s unusual death heralds the birth of compact neutron star binary, UC Santa Cruz   

    From Carnegie Institution for Science: “Massive star’s unusual death heralds the birth of compact neutron star binary” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    October 11, 2018


    Carnegie’s Anthony Piro was part of a Caltech-led team of astronomers who observed the peculiar death of a massive star that exploded in a surprisingly faint and rapidly fading supernova, possibly creating a compact neutron star binary system. Piro’s theoretical work provided crucial context for the discovery. Their findings are published by Science.

    Observations made by the Caltech team—including lead author Kishalay De and project principal investigator Mansi Kasliwal (herself a former-Carnegie postdoc)—suggest that the dying star had an unseen companion, which gravitationally siphoned away most of the star’s mass before it exploded as a supernova. The explosion is believed to have resulted in a neutron star binary, suggesting that, for the first time, scientists have witnessed the birth of a binary system like the one first observed to collide by Piro and a team of Carnegie and UC Santa Cruz astronomers in August 2017.

    A supernova occurs when a massive star—at least eight times the mass of the Sun—exhausts its nuclear fuel, causing the core to collapse and then rebound outward in a powerful explosion. After the star’s outer layers have been blasted away, all that remains is a dense neutron star—an exotic star about the size of a city but containing more mass than the Sun.

    Usually, a lot of material—many times the mass of the Sun—is observed to be blasted away in a supernova. However, the event that Kasliwal and her colleagues observed, dubbed iPTF 14gqr, ejected matter only one fifth of the Sun’s mass.

    “We saw this massive star’s core collapse, but we saw remarkably little mass ejected,” Kasliwal says. “We call this an ultra-stripped envelope supernova and it has long been predicted that they exist. This is the first time we have convincingly seen core collapse of a massive star that is so devoid of matter.”

    Piro’s theoretical modeling guided the interpretation of these observations. This allowed the observers to infer the presence of dense material surrounding the explosion.

    “Discoveries like this demonstrate why it has been so important to build a theoretical astrophysics group at Carnegie,” Piro said. “By combining observations and theory together, we can learn so much more about these amazing events.”

    The fact that the star exploded at all implies that it must have previously had a lot of material, or its core would never have grown large enough to collapse. But where was the missing mass hiding? The researchers inferred that the mass must have been stolen by a compact companion star, such as a white dwarf, neutron star, or black hole.

    The neutron star that was left behind from the supernova must have then been born into orbit with this compact companion. Because this new neutron star and its companion are so close together, they will eventually merge in a collision. In fact, the merger of two neutron stars was first observed in August 2017 by Piro and a team of Carnegie and UC Santa Cruz astronomers, and such events are thought to produce the heavy elements in our universe, such as gold, platinum, and uranium.

    The event was first seen at Palomar Observatory as part of the intermediate Palomar Transient Factory (iPTF), a nightly survey of the sky to look for transient, or short-lived, cosmic events like supernovae.

    Caltech Palomar Observatory, located in San Diego County, California, US, at 1,712 m (5,617 ft)

    Caltech Palomar Intermediate Palomar Transient Factory telescope at the Samuel Oschin Telescope at Palomar Observatory,located in San Diego County, California, United States

    Because the iPTF survey keeps such a close eye on the sky, iPTF 14gqr was observed in the very first hours after it had exploded. As the earth rotated and the Palomar telescope moved out of range, astronomers around the world collaborated to monitor iPTF 14gqr, continuously observing its evolution with a number of telescopes that today form the Global Relay of Observatories Watching Transients Happen (GROWTH) network of observatories.

    GROWTH map

    The three panels represent moments before, when and after the faint supernova iPTF14gqr, visible in the middle panel, appeared in the outskirts of a spiral galaxy located 920 million light years away from us. The massive star that died in the supernova left behind a neutron star in a very tight binary system. These dense stellar remnants will ultimately spiral into each other and merge in a spectacular explosion, giving off gravitational and electromagnetic waves. Image credit: SDSS/Caltech/Keck

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)

    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    See the full article here .


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    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

  • richardmitnick 4:00 pm on April 24, 2018 Permalink | Reply
    Tags: , , , , , , , UC Santa Cruz   

    From UC Santa Cruz: “Face recognition for galaxies: Artificial intelligence brings new tools to astronomy” 

    UC Santa Cruz

    UC Santa Cruz

    April 23, 2018
    Tim Stephens

    A ‘deep learning’ algorithm trained on images from cosmological simulations has been surprisingly successful at classifying real galaxies in Hubble images

    A ‘deep learning’ algorithm trained on images from cosmological simulations is surprisingly successful at classifying real galaxies in Hubble images. Top row: High-resolution images from a computer simulation of a young galaxy going through three phases of evolution (before, during, and after the “blue nugget” phase). Middle row: The same images from the computer simulation of a young galaxy in three phases of evolution as it would appear if observed by the Hubble Space Telescope. Bottom row: Hubble Space Telescope images of distant young galaxies classified by a deep learning algorithm trained to recognize the three phases of galaxy evolution. The width of each image is approximately 100,000 light years. [Image credits for top two rows: Greg Snyder, Space Telescope Science Institute, and Marc Huertas-Company, Paris Observatory. For bottom row: The HST images are from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS).

    A machine learning method called “deep learning,” which has been widely used in face recognition and other image- and speech-recognition applications, has shown promise in helping astronomers analyze images of galaxies and understand how they form and evolve.

    In a new study, accepted for publication in The Astrophysical Journal, researchers used computer simulations of galaxy formation to train a deep learning algorithm, which then proved surprisingly good at analyzing images of galaxies from the Hubble Space Telescope.

    The researchers used output from the simulations to generate mock images of simulated galaxies as they would look in observations by the Hubble Space Telescope. The mock images were used to train the deep learning system to recognize three key phases of galaxy evolution previously identified in the simulations. The researchers then gave the system a large set of actual Hubble images to classify.

    The results showed a remarkable level of consistency in the neural network’s classifications of simulated and real galaxies.

    “We were not expecting it to be all that successful. I’m amazed at how powerful this is,” said coauthor Joel Primack, professor emeritus of physics and a member of the Santa Cruz Institute for Particle Physics (SCIPP) at UC Santa Cruz. “We know the simulations have limitations, so we don’t want to make too strong a claim. But we don’t think this is just a lucky fluke.”

    Galaxies are complex phenomena, changing their appearance as they evolve over billions of years, and images of galaxies can provide only snapshots in time. Astronomers can look deeper into the universe and thereby “back in time” to see earlier galaxies (because of the time it takes light to travel cosmic distances), but following the evolution of an individual galaxy over time is only possible in simulations. Comparing simulated galaxies to observed galaxies can reveal important details of the actual galaxies and their likely histories.

    Blue nuggets

    In the new study, the researchers were particularly interested in a phenomenon seen in the simulations early in the evolution of gas-rich galaxies, when big flows of gas into the center of a galaxy fuel formation of a small, dense, star-forming region called a “blue nugget.” (Young, hot stars emit short “blue” wavelengths of light, so blue indicates a galaxy with active star formation, whereas older, cooler stars emit more “red” light.)

    In both simulated and observational data, the computer program found that the “blue nugget” phase only occurs in galaxies with masses within a certain range. This is followed by quenching of star formation in the central region, leading to a compact “red nugget” phase. The consistency of the mass range was an exciting finding, because it suggests the deep learning algorithm is identifying on its own a pattern that results from a key physical process happening in real galaxies.

    “It may be that in a certain size range, galaxies have just the right mass for this physical process to occur,” said coauthor David Koo, professor emeritus of astronomy and astrophysics at UC Santa Cruz.

    The researchers used state-of-the-art galaxy simulations (the VELA simulations) developed by Primack and an international team of collaborators, including Daniel Ceverino (University of Heidelberg), who ran the simulations, and Avishai Dekel (Hebrew University), who led analysis and interpretation of them and developed new physical concepts based on them. All such simulations are limited, however, in their ability to capture the complex physics of galaxy formation.

    In particular, the simulations used in this study did not include feedback from active galactic nuclei (injection of energy from radiation as gas is accreted by a central supermassive black hole). Many astronomers consider this process to be an important factor regulating star formation in galaxies. Nevertheless, observations of distant, young galaxies appear to show evidence of the phenomenon leading to the blue nugget phase seen in the simulations.


    CANDELS Cosmic Assembly Near Infrared Deep Extragalactic Legacy Survey

    For the observational data, the team used images of galaxies obtained through the CANDELS project (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey), the largest project in the history of the Hubble Space Telescope. First author Marc Huertas-Company, an astronomer at the Paris Observatory and Paris Diderot University, had already done pioneering work applying deep learning methods to galaxy classifications using publicly available CANDELS data.

    Koo, a CANDELS co-investigator, invited Huertas-Company to visit UC Santa Cruz to continue this work. Google has provided support for their work on deep learning in astronomy through gifts of research funds to Koo and Primack, allowing Huertas-Company to spend the past two summers in Santa Cruz, with plans for another visit in the summer of 2018.

    “This project was just one of several ideas we had,” Koo said. “We wanted to pick a process that theorists can define clearly based on the simulations, and that has something to do with how a galaxy looks, then have the deep learning algorithm look for it in the observations. We’re just beginning to explore this new way of doing research. It’s a new way of melding theory and observations.”

    For years, Primack has been working closely with Koo and other astronomers at UC Santa Cruz to compare his team’s simulations of galaxy formation and evolution with the CANDELS observations. “The VELA simulations have had a lot of success in terms of helping us understand the CANDELS observations,” Primack said. “Nobody has perfect simulations, though. As we continue this work, we will keep developing better simulations.”

    According to Koo, deep learning has the potential to reveal aspects of the observational data that humans can’t see. The downside is that the algorithm is like a “black box,” so it is hard to know what features in the data the machine is using to make its classifications. Network interrogation techniques can identify which pixels in an image contributed most to the classification, however, and the researchers tested one such method on their network.

    “Deep learning looks for patterns, and the machine can see patterns that are so complex that we humans don’t see them,” Koo said. “We want to do a lot more testing of this approach, but in this proof-of-concept study, the machine seemed to successfully find in the data the different stages of galaxy evolution identified in the simulations.”

    In the future, he said, astronomers will have much more observational data to analyze as a result of large survey projects and new telescopes such as the Large Synoptic Survey Telescope, the James Webb Space Telescope, and the Wide-Field Infrared Survey Telescope.

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

    NASA/ESA/CSA Webb Telescope annotated


    Deep learning and other machine learning methods could be powerful tools for making sense of these massive datasets.

    “This is the beginning of a very exciting time for using advanced artificial intelligence in astronomy,” Koo said.

    In addition to Primack, Koo, and Huertas-Company, the coauthors of the paper include Avishai Dekel at Hebrew University in Jerusalem (and a visiting researcher at UC Santa Cruz); Sharon Lapiner at Hebrew University; Daniel Ceverino at University of Heidelberg; Raymond Simons at Johns Hopkins University; Gregory Snyder at Space Telescope Science Institute; Mariangela Bernardi and H. Dominquez Sanchez at University of Pennsylvania; Zhu Chen at Shanghai Normal University; Christoph Lee at UC Santa Cruz; and Berta Margalef-Bentabol and Diego Tuccillo at the Paris Observatory.

    In addition to support from Google, this work was partly supported by grants from France-Israel PICS, US-Israel Binational Science Foundation, U.S. National Science Foundation, and Hubble Space Telescope. The VELA computer simulations were run on NASA’s Pleiades supercomputer and at DOE’s National Energy Research Scientific Computer Center (NERSC).

    NASA SGI Intel Advanced Supercomputing Center Pleiades Supercomputer

    NERSC Cray XC40 Cori II supercomputer

    LBL NERSC Cray XC30 Edison supercomputer

    The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.


    PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

    See the full article here .

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    UCO Lick Shane Telescope
    UCO Lick Shane Telescope interior
    Shane Telescope at UCO Lick Observatory, UCSC

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

    UC Santa Cruz campus
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

    UCSC is the home base for the Lick Observatory.

    Lick Observatory's Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building
    Lick Observatory’s Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building

    Search for extraterrestrial intelligence expands at Lick Observatory
    New instrument scans the sky for pulses of infrared light
    March 23, 2015
    By Hilary Lebow
    The NIROSETI instrument saw first light on the Nickel 1-meter Telescope at Lick Observatory on March 15, 2015. (Photo by Laurie Hatch) UCSC Lick Nickel telescope

    Astronomers are expanding the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light at UC’s Lick Observatory. A new instrument, called NIROSETI, will soon scour the sky for messages from other worlds.

    “Infrared light would be an excellent means of interstellar communication,” said Shelley Wright, an assistant professor of physics at UC San Diego who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics.

    Wright worked on an earlier SETI project at Lick Observatory as a UC Santa Cruz undergraduate, when she built an optical instrument designed by UC Berkeley researchers. The infrared project takes advantage of new technology not available for that first optical search.

    Infrared light would be a good way for extraterrestrials to get our attention here on Earth, since pulses from a powerful infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from great distances. It also takes less energy to send information using infrared signals than with visible light.

    UCSC alumna Shelley Wright, now an assistant professor of physics at UC San Diego, discusses the dichroic filter of the NIROSETI instrument. (Photo by Laurie Hatch)

    Frank Drake, professor emeritus of astronomy and astrophysics at UC Santa Cruz and director emeritus of the SETI Institute, said there are several additional advantages to a search in the infrared realm.

    “The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success,” said Drake.

    The only downside is that extraterrestrials would need to be transmitting their signals in our direction, Drake said, though he sees this as a positive side to that limitation. “If we get a signal from someone who’s aiming for us, it could mean there’s altruism in the universe. I like that idea. If they want to be friendly, that’s who we will find.”

    Scientists have searched the skies for radio signals for more than 50 years and expanded their search into the optical realm more than a decade ago. The idea of searching in the infrared is not a new one, but instruments capable of capturing pulses of infrared light only recently became available.

    “We had to wait,” Wright said. “I spent eight years waiting and watching as new technology emerged.”

    Now that technology has caught up, the search will extend to stars thousands of light years away, rather than just hundreds. NIROSETI, or Near-Infrared Optical Search for Extraterrestrial Intelligence, could also uncover new information about the physical universe.

    “This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales,” said Dan Werthimer, UC Berkeley SETI Project Director. “The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone.”

    NIROSETI will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed for potential signs of other civilizations.

    “Searching for intelligent life in the universe is both thrilling and somewhat unorthodox,” said Claire Max, director of UC Observatories and professor of astronomy and astrophysics at UC Santa Cruz. “Lick Observatory has already been the site of several previous SETI searches, so this is a very exciting addition to the current research taking place.”

    NIROSETI will be fully operational by early summer and will scan the skies several times a week on the Nickel 1-meter telescope at Lick Observatory, located on Mt. Hamilton east of San Jose.

    The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley; Patrick Dorval, a Dunlap undergraduate, and Elliot Meyer, a Dunlap graduate student; and Richard Treffers of Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield.

  • richardmitnick 2:11 pm on July 26, 2016 Permalink | Reply
    Tags: , , Pacific Collegiate School student Spencer Cheleden, Soquel teen develops new technology for astronomical telescopes, UC Santa Cruz   

    From Santa Cruz Sentinel via UC Santa Cruz: “Soquel teen develops new technology for astronomical telescopes” 

    UC Santa Cruz

    UC Santa Cruz

    Santa Cruz Sentinel

    Ryan Masters

    Pacific Collegiate School student Spencer Cheleden has developed a new way to coat the enormous astronomical telescope mirrors during his summer research at UC Santa Cruz with research astronomer mentor Andrew Phillips. (Dan Coyro — Santa Cruz Sentinel)

    While most teenagers play Pokémon Go this summer, Spencer Cheleden is discovering ways to improve the world’s most powerful astronomical telescopes.

    Under the mentorship of Andrew Phillips, who heads up the Advanced Coatings Lab at the University of California Observatories, Cheleden, began experimenting with silver-based reflective coatings on telescope mirrors in the fall of 2015 as part of UC Santa Cruz’s Science Internship Program.

    Optical coatings are thin films applied to mirror and lens surfaces to enhance reflection for mirrors. They can consist of one or multiple layers of various materials, and are roughly 200 to 400 nanometers in thickness — or 1/300 the diameter of a human hair.

    “Dr. Phillips outlined his research for me last summer and gave me a choice of projects. Silver-based reflective coatings had been sort of a dormant area of research and I became interested in improving the efficiency of the telescopes to create more light and more data,” said Cheleden, 17, who will be a senior at Pacific Collegiate School in the fall.

    Telescope mirrors traditionally have aluminum-based coatings, Cheleden said. Silver has been largely overlooked as a coating material because it tarnishes when exposed to oxygen. To protect the thin film of silver from oxidation, Phillips and Cheleden began experimenting with a variety of metal oxide, fluoride and nitride applications.

    “If you spray it clear over the silver, it maintains its reflecting properties and also protects from water and abrasion,” Cheleden said.

    This summer, Phillips and Cheleden have been creating composites using promising materials such as titanium oxide, hafnium oxide, silicon nitride and yttrium fluoride. To see which composite protects the silver reflecting surface longest and best, these coatings are being tested in a lab on the UCSC campus as well as in real-world situations such as a Lick Observatory telescope.

    Phillips and Cheleden already have co-published results in the Journal of Astronomical Telescopes, Instruments and Systems, a paper that Phillips also presented at a conference in Scotland. Cheleden says they hope to have a second paper published this year.

    In addition, Cheleden won first place in physics and astronomy at the 2016 California State Science Fair and received the Optics and Photonics Award from SPIE, the International Society for Optics and Photonics.

    His project was so outstanding that the University of Toronto’s engineering department selected him to attend a weeklong elite engineering summer camp in Toronto this year where he studied cleaner combustion engines for aerospace.

    Despite the accolades and success, Cheleden said he probably won’t pursue physics or astronomy in the future. While he dreams of attending Stanford University after high school, he doesn’t foresee a career in academia.

    “I see myself using applied mathematics in finance or consulting,” Cheleden said. “Maybe running a company offering computer-based solutions.”

    See the full article here .

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    UCO Lick Shane Telescope
    UCO Lick Shane Telescope interior
    Shane Telescope at UCO Lick Observatory, UCSC/em>

    UC Santa Cruz campus
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

  • richardmitnick 6:36 pm on July 7, 2016 Permalink | Reply
    Tags: , , Exploring a Frozen Extrasolar World, , UC Santa Cruz   

    From Gemini: “Exploring a Frozen Extrasolar World” 


    Gemini Observatory
    Gemini Observatory

    July 6, 2016
    Media Contacts:

    Peter Michaud
    Public Information and Outreach
    Gemini Observatory, Hilo, HI
    Email: pmichaud”at”gemini.edu
    Cell: (808) 936-6643

    Tim Stephens
    University of California, Santa Cruz
    Email: stephens”at”ucsc.edu
    Phone: (831) 459-4352

    Science Contacts:

    Andrew Skemer
    University of California, Santa Cruz
    Email: askemer”at”ucsc.edu
    Phone: (831) 459-5753

    Jacqueline Faherty
    Hubble Postdoctoral Fellow
    Carnegie Institution for Science
    Email: jfaherty17″at”gmail.com
    Cell: (201) 694-0807

    Sandy Leggett
    Gemini Observatory
    Email: sleggett”at”gemini.edu
    Phone: (808) 974-2604

    Artist’s conception of how WISE 0855 might appear if viewed close-up in infrared light. Artwork by Joy Pollard, Gemini Observatory/AURA.

    University of California, Santa Cruz press release. [This is definitely worth reading, but, finding the Gemini article, I was bound to use it.]

    First Evidence for Water Ice Clouds Found outside Solar System
    Access mp4 video here .

    Astronomers have “cracked” a very cold case with the dissection of light from the coldest known brown dwarf. In fact, the brown dwarf, named WISE 0855, is billed as the most frigid discrete world yet discovered beyond our Solar System. The research also presents the strongest evidence yet for water clouds in the atmosphere of an extrasolar object.

    The history of “failed stars” having masses between that of a star and planet – called brown dwarfs – continues to blur. Now, that distinction is even more ambiguous with the confirmation that WISE 0855 shares more of a likeness with Jupiter than many exoplanets.

    New evidence for this comes from the first spectroscopy, or light fingerprint, of the object, performed at the Gemini North telescope in Hawai’i. The spectrum presents astronomers with the most definitive evidence ever for water vapor in the atmosphere of an object outside of our solar system. The research also confirms that temperatures dip to about 20 below zero Celsius (-10 degrees F) in its cold atmosphere.

    WISE 0855 was discovered by Kevin Luhman of Penn State in 2014 using data from NASA’s Wide-field Infrared Survey Explorer (WISE) satellite.

    NASA/Wise Telescope
    NASA/Wise Telescope

    WISE 0855’s relatively close proximity – it’s only about 7.2 light years away, the fourth closest extrasolar object to the Sun – provides an advantage in capturing the object’s miniscule glow; however, it is still remarkably difficult to observe.

    “It’s five times fainter than any other object detected with ground-based spectroscopy at this wavelength,” said Andy Skemer of the University of California Santa Cruz. “Now that we have a spectrum, we can really start thinking about what’s going on in this object. Our spectrum shows that WISE 0855 is dominated by water vapor and clouds, with an overall appearance that is strikingly similar to Jupiter.” Skemer is first author of a paper on the new findings to be published in Astrophysical Journal Letters and currently available online.

    “I think everyone on the research team really believed that we were dreaming to think we could obtain a spectrum of this brown dwarf because its thermal glow is so feeble,” said Skemer. WISE 0855, is so cool and faint that many astronomers thought it would be years before we could dissect its diminutive light into a spectrum. “I thought we’d have to wait until the James Webb Space Telescope was operating to do this,” adds Skemer.

    The spectrum, obtained using the Gemini North telescope on Hawaii’s Maunakea, was obtained over a period of 13 nights (about 14 hours of data collection). “These observations could only be done on a facility like Gemini North. This is due to its location on Maunakea, where there is often remarkably little water vapor in the air to interfere with the sensitive observations, and the technology on the telescope, like its 8-meter silver-coated mirror,” says Jacqueline Faherty of the Carnegie Department of Terrestrial Magnetism. “We pushed the boundary of what could be done with a telescope here on Earth. And the result is spectacular.”

    The resulting high-quality spectrum reveals water vapor and clouds in the object’s atmosphere, and opens opportunities to explore the atmosphere’s dynamics and chemistry. Gemini astronomer, and brown dwarf researcher, Sandy Leggett explains that the spectrum shows less phosphine than we see in Jupiter, “…suggesting that the atmosphere may be less turbulent, since mixing produces the phosphine seen in Jupiter’s atmosphere.”

    Results from previous observations of WISE 0855, published in 2014, provided hints of water clouds based on very limited photometric data (the relative brightness of specific wavelengths of light). Skemer, also a coauthor of the 2014 paper, adds that with spectroscopy scientists are able to separate the object’s light into a wide range of infrared wavelengths, and probe the body’s molecular composition. “If our eyes could see infrared light, which is redder than the reddest light we can see, the data would look like a rainbow of colors.” He adds, “The relative brightness of each color gives us a glimpse into the environment of the object’s atmosphere.”

    The coauthors of the study include graduate student Caroline Morley and professor of astronomy and astrophysics Jonathan Fortney at UC Santa Cruz; Katelyn Allers at Bucknell University; Thomas Geballe at Gemini Observatory; Mark Marley and Roxana Lupu at NASA Ames Research Center; Jacqueline Faherty at the Carnegie Institution of Washington; and Gordon Bjoraker at NASA Goddard Space Flight Center.

    Observations for this work were made using the Gemini Near-InfraRed Spectrograph (GNIRS) which is mounted on the Gemini North telescope on Maunakea in Hawai‘i.

    Gemini Near-InfraRed Spectrograph (GNIRS)

    The research team, and Gemini staff, are grateful to be able to observe from Maunakea, Hawaii’s highest peak, where conditions are ideal for these types of observations.

    See the full article here .

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    Gemini’s mission is to advance our knowledge of the Universe by providing the international Gemini Community with forefront access to the entire sky.

    The Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai’i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.

    The Gemini Observatory provides the astronomical communities in six partner countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country’s contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Australian Research Council (ARC), the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva, and the Brazilian Ministério da Ciência, Tecnologia e Inovação. The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.

  • richardmitnick 4:21 pm on June 8, 2016 Permalink | Reply
    Tags: , , Jennifer Burt, Lick APF, UC Santa Cruz,   

    From UCSC: Women in Science “The sky is no limit for planet-hunting grad student” 

    UC Santa Cruz

    UC Santa Cruz

    June 07, 2016
    Peggy Townsend

    Astronomy student Jennifer Burt helped write software that turned a powerful telescope at Lick Observatory into the first automated planet finder in the world.

    Grad student Jennifer Burt, above, “played the linchpin role in writing the software that puts the ‘A’ in the APF (Automated Planet Finder) Telescope,” said Greg Laughlin, professor of astronomy and astrophysics. (Photo by Carolyn Lagattuta)

    Every night for a year, astronomy graduate student Jennifer Burt would settle into a small room on the UC Santa Cruz campus and begin her job as a planet hunter.

    While most people slept, Burt would examine weather, atmospheric conditions, and time of year before deciding which stars on a long list of possibilities would be the best targets for a powerful telescope located at Lick Observatory on Mount Hamilton. A run of fingers over computer keys would then start the telescope searching portions of the night sky for its prey: planets that orbited stars beyond our solar system.

    “After a year,” said the 28-year-old with a laugh, “I thought maybe we should automate this thing because I would like to sleep at night.”

    Which is exactly what the competitive ballroom dancer and former Cornell University grad did. She went to work helping write software that turned the $12 million telescope into a robotic version of herself. It became the first automated planet finder in the world.

    “Jenn played the linchpin role in writing the software that puts the ‘A’ in the APF (Automated Planet Finder) Telescope,” says Greg Laughlin, professor of astronomy and astrophysics at UC Santa Cruz. “With hard-won night after night of on-sky experience, she was able to gain a full understanding of all the nuances, subtleties, and contingencies that occur in the course of operations. She was then able to fully translate this intuitive understanding into the stark, fully defined logical structure that permits a computer to take over the night-to-night role of a human observer.”

    Soon, however, Burt will give up the redwoods of Santa Cruz for the historic streets of Cambridge, Mass., where she won a post-doc fellowship at the Massachusetts Institute of Technology and hopes to work on a NASA project aimed at discovering more about these so-called extrasolar planets or exoplanets. The project, dubbed TESS (Transiting Exoplanet Survey Satellite), is designed to determine the radii and orbits of the planets it detects. More than 3,000 have already been discovered.


    With nearby Harvard also taking part in the project, “it’s a cool place to be for someone like me,” Burt says. She notes however, the opportunity might not have happened without the guidance of her UC Santa Cruz mentors and a $10,000 scholarship from the Achievement Rewards for College Scientists (ARCS) Foundation.

    Tall, with long, dark hair and a way of explaining astronomy that can make even a science-phobe get excited about stargazing, Burt came to her career thanks to an old telescope set up at a family cabin in the Adirondacks and an energetic teacher who ran a NASA club at her high school in upstate New York. A club visit to Arizona State University, where NASA projects were being undertaken, sealed her fate.

    “That trip made it clear early on for me that astronomy was a viable career path,” Burt says.

    At Cornell, Burt’s attention was grabbed by the emerging field of exoplanet research, which led her to UC Santa Cruz and two professors of astronomy and astrophysics, Laughlin and Steve Vogt. Here, she began her nocturnal planet detecting with the result that her team was able to discover three different planetary systems using the APF telescope.

    UC Observatories Lick APF
    UC Observatories Lick APF

    The finding that most electrifies her was the detection of six planets orbiting a nearby star with the decidedly un-electrifying name of HD219134.

    “It’s especially exciting because the star is very bright so we can do a lot of follow-up studies,” Burt says. “The second thing that makes it cool is that at the same time we found six planets, another team in Switzerland found the same system but it had only seen the inner four planets.”

    Burt also is credited with locating a Neptune-sized planet orbiting a red dwarf star, and, while she admits there was nothing exceptional about this particular planet, the discovery showed the APF is designed perfectly for its job, which is to find even the most common planets.

    For Burt, who sports a star-shaped ring and a galactic-themed cell phone cover, the future holds the promise of discovering more about these exoplanets: their properties, their origin and, as always, whether there are other habitable Earth-sized planets out there.

    Delving into far-flung mysteries is exactly the place a sci-fi-loving scientist like Burt wants to find herself. But she wouldn’t have arrived, she says, without the ARCS scholarship—which allowed her to travel to meet prominent people in the field, resulting in a post-doctoral position—and also without the help of Laughlin and Vogt.

    Burt, who also coached the UC Santa Cruz ballroom dance team and designed a training program for teaching assistants on campus, says Vogt “taught me everything I know about finding planets” while Laughlin, a theorist, “taught me to look for the big science questions that were interesting.”

    “Any scientist’s eventual success is based, in part, on the people who supported them along the way,” Burt says. “I’ve been extremely fortunate to work with advisors who were always willing to share their knowledge, while also continually pushing me to become a better researcher.

    “That’s a huge advantage when you’re starting out.”

    See the full article here .

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    UCO Lick Shane Telescope
    UCO Lick Shane Telescope interior
    Shane Telescope at UCO Lick Observatory, UCSC/em>

    UC Santa Cruz campus
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

  • richardmitnick 2:16 pm on May 14, 2016 Permalink | Reply
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    From UCSC: “Astronomer Sandra Faber to receive honorary degree from Amherst College” 

    UC Santa Cruz

    UC Santa Cruz

    May 13, 2016
    Tim Stephens

    Sandy Faber

    Astronomer Sandra Faber will receive an honorary degree from Amherst College during its 195th commencement exercises on Sunday, May 22. Amherst President Biddy Martin will deliver the address during the ceremony, and Faber and the other honorees will speak in a series of public conversations.

    A professor emeritus of astronomy and astrophysics at UC Santa Cruz, Faber is known for her pioneering research on the formation and evolution of galaxies, distant galaxy clusters, and the large-scale structure of the universe. She is also a leading authority on telescopes and astronomical instrumentation and has been closely involved with both the Hubble Space Telescope and the W. M. Keck Observatory in Hawaii.

    NASA/ESA Hubble Telescope
    NASA/ESA Hubble Telescope

    Keck Observatory, Mauna Kea, Hawaii, USA
    Keck Observatory Interior
    Keck Observatory

    Among her many contributions to astronomy is the Faber-Jackson relation, the first known structural scaling law for galaxies—in this case, the relation between the mass of a galaxy and the speed of stars that orbit within it.

    Velocity dispersion (y-axis) plotted against absolute magnitude (x-axis) for a sample of elliptical galaxies, with the Faber–Jackson relation shown in blue.
    Plot of the Faber-Jackson relation for elliptical galaxies, using data from the original paper by Faber & Jackson (1976)

    In addition, Faber’s work has uncovered huge irregularities in the expansion of the universe caused by the perturbing effects of gravity from superclusters of galaxies. With colleagues, she used the Hubble Space Telescope to penetrate the cores of galaxies, revealing massive black holes at their centers. She has led major efforts with both Hubble and Keck to survey thousands of distant galaxies to characterize and document the evolution of galaxies over the history of the universe.

    Faber, who joined the UCSC faculty in 1972, holds a bachelor’s degree in physics from Swarthmore and a Ph.D. in astronomy from Harvard. She has received many awards and honors in recognition of her accomplishments, including the National Medal of Science, the Franklin Institute’s Bower Award and Prize for Achievement in Science, and two awards for lifetime scientific achievement, the Bruce Medal of the Astronomical Society of the Pacific and the Russell Prize of the American Astronomical Society. She is a member of the National Academy of Sciences, American Academy of Arts and Sciences, and American Philosophical Society.

    See the full article here .

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    UCO Lick Shane Telescope
    UCO Lick Shane Telescope interior
    Shane Telescope at UCO Lick Observatory, UCSC/em>

    UC Santa Cruz campus
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

  • richardmitnick 2:38 pm on May 6, 2016 Permalink | Reply
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    From UCSC: “Shallow slow-motion earthquakes detected offshore of New Zealand” 

    UC Santa Cruz

    UC Santa Cruz

    May 05, 2016
    Tim Stephens

    An international team of scientists deployed a network of seafloor instruments, including seismometers and pressure gauges, offshore Gisborne, New Zealand, from the R/V Tangaroa. (Photo by Takeo Yagi, University of Tokyo)

    The Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) detected a slow slip event at the Hikurangi subduction zone, where the Pacific Plate dives beneath New Zealand’s North Island. (Image credit: GNS Science/Laura Martin)

    Research published* in the May 6 issue of Science indicates that slow-motion earthquakes or “slow-slip events” can rupture the shallow portion of a fault that also moves in large, tsunami-generating earthquakes. The finding has important implications for assessing tsunami hazards. The discovery was made by conducting the first-ever detailed investigation of centimeter-level seafloor movement at an offshore subduction zone.

    “We’ve previously used land-based instruments to detect slow-slip events, but this is the first time we’ve been able to document slow slip in the shallow portion of an offshore subduction zone. With instruments on the seafloor right above the plate boundary, we now have very high-resolution mapping of where the slip occurred,” said coauthor Susan Schwartz, professor of Earth and planetary sciences at UC Santa Cruz.

    First author Laura Wallace, a research scientist at The University of Texas at Austin’s Institute for Geophysics, led an international team of researchers from the United States, Japan, and New Zealand in the collaborative research project. “These data have revealed the true extent of slow-motion earthquakes at an offshore subduction zone for the first time,” said Wallace, who earned her Ph.D. at UC Santa Cruz in 2002.

    Subduction zone

    The world’s most devastating tsunamis are generated by earthquakes that occur near the trenches of subduction zones, places where one tectonic plate begins to dive or “subduct” beneath another. Using a network of highly-sensitive seafloor pressure recorders, the team detected a slow-slip event in September 2014 off the east coast of New Zealand. The study was undertaken at the Hikurangi subduction zone, where the Pacific Plate subducts beneath New Zealand’s North Island.

    The slow-slip event lasted two weeks, resulting in 15 to 20 centimeters of movement along the fault that lies between New Zealand and the Pacific Plate, a distance equivalent to three to four years of background plate motion. If the movement had occurred suddenly, rather than slowly, it would have resulted in a magnitude 6.8 earthquake. The seafloor sensors recorded up to 5.5 centimeters (about 2 inches) of upward movement of the seafloor during the event.

    Slow-slip events are similar to earthquakes, but instead of releasing strain between two tectonic plates in seconds, they do it over days to weeks, creating quiet, centimeter-sized shifts in the landscape. In a few cases, these small shifts have been associated with setting off destructive earthquakes. The slow-slip event that the team studied occurred in the same location as a magnitude 7.2 earthquake in 1947 that generated a large tsunami. The study shows that the two types of seismic events can occur on the same part of a plate boundary.


    The link has been difficult to document in the past because most slow-slip monitoring networks are land-based and are located far from the trenches that host tsunami-generating earthquakes, Wallace said. The data for this study was recorded by HOBITSS, a temporary underwater network that monitored slow-slip events by recording vertical movement of the seafloor. HOBITSS stands for “Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip.”

    “Our results clearly show that shallow, slow-slip event source areas are also capable of hosting seismic rupture and generating tsunamis,” said coauthor Yoshihiro Ito, a professor at Kyoto University. “This increases the need to continuously monitor shallow, offshore slow-slip events at subduction zones, using permanent monitoring networks similar to those that have been established offshore of Japan.”

    According to Schwartz, the demonstration that pressure sensors on the seafloor can be used to accurately measure the deformation associated with slow-slip events is an important proof of concept. “The ultimate goal is to map the mechanical properties of the shallow plate interface and understand what areas have the potential to slip in ways that produce damaging earthquakes, tsunami-generating earthquakes, or slow slip,” she said.

    Earthquakes are unpredictable events, Wallace said, but the linkage between slow-slip events and earthquakes could eventually help in forecasting the likelihood of damaging earthquakes. “To do that we will have to understand the links between slow-slip events and earthquakes much better than we currently do,” Wallace said.

    The research team installed the HOBITSS network in May 2014, which consisted of 24 seafloor pressure gauges, and 15 ocean bottom seismometers. The team collected the devices and data in June 2015.

    Additional participants included scientists from the University of Tokyo, Tohoku University, GNS Science, and the University of Colorado Boulder. The research was funded by the National Science Foundation; the Japan Society for Promotion of Science; Japan’s Ministry of Education, Culture, Sports, Science and Technology; and grants from participating universities and research institutions.

    *Science paper:
    Slow slip near the trench at the Hikurangi subduction zone, New Zealand

    See the full article here .

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    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

  • richardmitnick 3:10 pm on April 8, 2016 Permalink | Reply
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    From AAS NOVA: ” How Bright Can Supernovae Get?” 


    American Astronomical Society

    Supernova remnant W49B. The highly distorted supernova remnant shown in this image may contain the most recent black hole formed in the Milky Way galaxy. The image combines X-rays from NASA’s Chandra X-ray Observatory in blue and green, radio data from the NSF’s Very Large Array in pink, and infrared data from Caltech’s Palomar Observatory in yellow. (X-ray: NASA/CXC/MIT/L.Lopez et al; Infrared: Palomar; Radio: NSF/NRAO/VLA)

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    Caltech Palomar 200 inch Hale Telescope
    Caltech Palomar 200 inch Hale Telescope interior
    Caltech Palomar 200 inch Hale Telescope


    Supernovae — enormous explosions associated with the end of a star’s life — come in a variety of types with different origins. A new study has examined how the brightest supernovae in the Universe are produced, and what limits might be set on their brightness.

    Ultra-Luminous Observations

    Recent observations have revealed many ultra-luminous supernovae, which have energies that challenge our abilities to explain them using current supernova models. An especially extreme example is the 2015 discovery of the supernova ASASSN-15lh, which shone with a peak luminosity of ~2*1045 erg/s, nearly a trillion times brighter than the Sun. ASASSN-15lh radiated a whopping ~2*1052 erg in the first four months after its detection.

    How could a supernova that bright be produced? To explore the answer to that question, Tuguldur Sukhbold and Stan Woosley at University of California, Santa Cruz, have examined the different sources that could produce supernovae and calculated upper limits on the potential luminosities of each of these supernova varieties.

    Explosive Models

    Sukhbold and Woosley explore multiple different models for core-collapse supernova explosions, including:

    Prompt explosion
    A star’s core collapses and immediately explodes.

    Pair instability
    Electron/positron pair production at a massive star’s center leads to core collapse. For high masses, radioactivity can contribute to delayed energy output.

    Colliding shells
    Previously expelled shells of material around a star collide after the initial explosion, providing additional energy release.

    The collapsing star forms a magnetar — a rapidly rotating neutron star with an incredibly strong magnetic field — at its core, which then dumps energy into the supernova ejecta, further brightening the explosion.

    They then apply these models to different types of stars.

    Setting the Limit

    The authors show that the light curve of ASASSN-15lh (plotted in orange) can be described by a model (black curve) in which a magnetar with an initial spin period of 0.7 ms and a magnetic field of 2*1013 Gauss deposits energy into ~12 solar masses of ejecta. Click for a closer look! [Adapted from Sukhbold&Woosley 2016]

    The authors find that the maximum luminosity that can be produced by these different supernova models ranges between 5*1043 and 2*1046 erg/s, with total radiated energies of 3*1050 to 4*1052 erg. This places the upper limit on the brightness of a supernova at about 5 trillion times the luminosity of the Sun.

    The calculations performed by Sukhbold and Woosley confirm that, of the options they explore, the least luminous events are produced by prompt explosions. The brightest events possible are powered by the rotational energy of a newly born magnetar at the heart of the explosion.

    The energies of observed ultra-luminous supernovae are (just barely) contained within the bounds of the mechanisms explored here. This is even true of the extreme ASASSN-15lh — which, based on the authors’ calculations, was almost certainly powered by an embedded magnetar. If we were to observe a supernova more than twice as bright as ASASSN-15lh, however, it would be nearly impossible to explain with current models.

    Tuguldur Sukhbold and S. E. Woosley 2016 ApJ 820 L38. doi:10.3847/2041-8205/820/2/L38

    Science Paper:

    Science team:
    Tuguldur Sukhbold, S. E. Woosley

    Author affiliations
    Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA
    UC Santa Cruz Dept of Astronomy and Astrophysics

    See the full article here .

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  • richardmitnick 11:07 am on March 11, 2016 Permalink | Reply
    Tags: , , Milky Way Halo of old stars, , UC Santa Cruz   

    From SKY & Telescope: “Galactic Archaelogy in the Milky Way Halo” 

    SKY&Telescope bloc

    Sky & Telescope

    March 10, 2016
    Monica Young

    MIlky Way Halo NASA ESA STScI
    Milky Way surrounded by halo of 13 old stars

    Thirteen lonely stars in the outer reaches of the Milky Way may hold clues to our galaxy’s formation. New research shows that they might be part of a shell-shaped relic that marks an ancient run-in with a dwarf galaxy.

    In the galactic disk, gas and stars circle the center in orderly orbits, but the same can’t be said of the cloud of stars that surround the Milky Way. Theorists think most of these so-called halo stars were born in a multitude of dwarf galaxies that were later devoured by our own. Now these stars follow orbits that take them in and out of our galaxy’s center rather than around it. At such great distances, these stars move in slow motion, just as Pluto moves far more slowly in its orbit than flighty Mercury, so their orbits “remember” their ancient origins.

    Digging Up Relics in Milky Way’s Halo

    Three years ago, Alis Deason (then at University of California, Santa Cruz) led a team in measuring the motions of halo stars across the sky. The team took advantage of a Hubble Space Telescope program that was observing the Andromeda Galaxy.

    NASA Hubble Telescope
    NASA/ESA Hubble

    Andromeda Galaxy

    Picking out a baker’s dozen of foreground stars that lie in front of Andromeda, Deason and colleagues watched their sideways motion over a period of five to seven years.

    Though exact measures of distance aren’t available, these stars are about 65,000 light-years from the center of the Milky Way: square in our galaxy’s halo, which extends out some 300,000 light-years.

    “Watching the motion of stars across the face of galaxies is analogous to watching human hair grow on the surface of the Moon as seen from Earth,” says Puragra Guha Thakurta (University of California, Santa Cruz). Yet, he notes, it’s doable.

    But the measurements from Deason’s team only gave stellar motions in two dimensions. This year, Emily Cunningham (University of California, Santa Cruz) took on the mantle, leading an effort to collect each star’s spectrum, looking for the shift in spectral lines that would reveal their motions along our line of sight.

    Cunningham’s team confirms that these 13 stars defy expectations: they’re not traveling along paths that take them straight into or out of our galaxy. Most likely, they’re part of a shell of stars that are piling up as they turn around in their in-and-out orbits.

    “If we are correct in our interpretation of a shell, this shell would be a relic from a past accretion event,” says Cunningham. This shell would be all that’s left of a dwarf galaxy, or perhaps even a group of dwarfs, that fell into the Milky Way’s gravitational grasp several billion years ago.

    The alternative is that the stars are actually forming out there, in the farthest corners of the Milky Way. But as James Bullock says, “It’s hard to imagine stars forming out there in regions of such low density.” Moreover, he adds, “cosmological models predict that shells like this should be out there.”

    The Future of Galactic Archaeology

    Ultimately, though, 13 stars is a pretty small sample with which to dig up our galaxy’s history. That’s why Cunningham, Deason, and colleagues are planning a much larger sample in a project known as HALO7D, which will contain information on hundreds of halo stars once observations are complete.

    HALO7D: Looking at and Through the Milky Way – Raja GuhaThakurta
    Access the mp4 video here .

    Bullock, whose simulations have outlined our galaxy’s formation history, is excited to see the results of this and other studies. “We aim to figure out what kinds of smaller galaxies fell into the Milk Way (How big were they? What kind of stars were they made of?), and also when those galaxies fell in.”

    But even the grandest cosmic implications can’t prevent more prosaic considerations. “We are completely at the mercy of the weather,” says Cunningham. Cloudy nights disrupted plans to finish collecting data last spring, so observing will continue this spring and next, with final results one to two years from now.

    See the full article here .

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    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

  • richardmitnick 3:13 pm on February 20, 2016 Permalink | Reply
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    From UCSC: “Astronomers plan science projects for powerful new space telescope” 

    UC Santa Cruz

    UC Santa Cruz

    February 18, 2016
    Tim Stephens

    NASA begins formal development of the Wide Field Infrared Survey Telescope (WFIRST), planned to launch in the mid-2020s


    Download mp4 video here .
    The Wide Field Infrared Survey Telescope (WFIRST) will image large regions of the sky in near-infrared light to answer fundamental questions about the structure and evolution of the universe and greatly expand our knowledge of planetary systems around other stars. (Credit: NASA’s Goddard Space Flight Center)

    A team of astronomers is beginning to plan projects and strategies for making the best use of a powerful new space telescope now under development by NASA.

    NASA announced the formal start of the Wide Field Infrared Survey Telescope (WFIRST) mission on February 18. Planned as the agency’s next major astrophysics observatory following the launch of the James Webb Space Telescope [JWST], WFIRST will survey large regions of the sky in near-infrared light to answer fundamental questions about the structure and evolution of the universe and to expand our knowledge of planetary systems around other stars.

    NASA Webb telescope annotated

    Brant Robertson, associate professor of astronomy and astrophysics at UC Santa Cruz, leads the WFIRST Extragalactic Potential Observations (EXPO) Science Investigation Team, which will identify the most pressing and scientifically compelling projects for WFIRST beyond the primary survey projects already planned for the telescope.

    “There will be a huge amount of data from the surveys, and part of our job is to think about how we can make that data most useful for general astronomers in order to optimize the science payoffs,” Robertson said. “We are also helping to evaluate the design of the telescope, running simulations of how it will work and analyzing simulated images.”

    Wide Field Instrument

    WFIRST incorporates components from an existing telescope NASA acquired from another agency in 2012, including a 2.4-meter mirror of identical size and quality to the one used by the Hubble Space Telescope. The telescope’s Wide Field Instrument will give it the ability to capture a single image with the depth and quality of Hubble but covering 100 times Hubble’s field of view. WFIRST will also carry a Coronagraph Instrument designed to block the glare of individual stars and reveal the faint light of planets orbiting around them.

    “The design work is already well advanced, and it is a really impressive telescope,” Robertson said. “Its camera is about 200 times larger than Hubble’s, and this capability will enable astronomers around the world to use WFIRST to explore the deepest reaches of space over an area thousands of times larger than the size of the moon on the sky.”

    Guest investigators will be able to conduct their own investigations using data from the surveys, while guest observers can propose additional survey projects for the telescope. The WFIRST-EXPO team will evaluate guest investigator and guest observer projects to help maximize the scientific return of the WFIRST cosmological surveys and realize the full power of the telescope for extragalactic astronomy. The team, one of a dozen WFIRST science investigation teams, will receive $2.3 million to perform these studies over the next five years.

    Robertson leads the team of 11 astronomers, including world-wide experts in designing and executing space-based extragalactic survey programs, multi-object spectroscopic campaigns in optical and infrared wavelengths, and theoretical modeling of galaxy formation, exotic supernovae, and cosmic reionization. They include Piero Madau and Stan Woosley at UC Santa Cruz; Dan Marrone and Daniel Stark at the University of Arizona; Risa Wechsler at Stanford University; Jenny Greene at Princeton University; Steven Furlanetto and Alice Shapley at UCLA; Henry Ferguson at the Space Science Telescope Institute; and Mark Dickinson at the Association of Universities for Research in Astronomy.

    In addition to surveys of deep space beyond our galaxy, WFIRST’s sensitivity and wide field of view will enable a large-scale search for exoplanets by monitoring the brightness of millions of stars in the crowded central region of our galaxy. The survey will net thousands of new exoplanets, complementing the work started by NASA’s Kepler mission and the upcoming work of the Transiting Exoplanet Survey Satellite.

    Other wide-field surveys will enable astronomers to track how dark energy and dark matter have affected the expansion of the universe over the past 10 billion years or more. By measuring the distances to thousands of supernovae, astronomers can map in detail how cosmic expansion has increased with time. WFIRST can also precisely measure the shapes, positions and distances of millions of galaxies to track the distribution and growth of cosmic structures.


    The Coronagraph Instrument will enable detailed measurements of the chemical makeup of planetary atmospheres. Comparing this data across many worlds will allow scientists to better understand the origin and physics of their atmospheres and to search for chemical signs of environments suitable for life.

    “In addition to its exciting capabilities for dark energy and exoplanets, WFIRST will provide a treasure trove of exquisite data for all astronomers,” said Neil Gehrels, the WFIRST Project Scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This mission will survey the universe to find the most interesting objects out there.”

    The James Webb Space Telescope (JWST), planned to launch in 2018, will see deeper into space and further back in time than WFIRST. With its larger mirror, JWST will be able to observe much fainter galaxies, but its field of view is much smaller.

    NASA Hubble mirror vs Webb mirror
    On the left, Hubble’s mirror; on the right JWST’s mirror

    “JWST will conduct very deep observations of a small area, while WFIRST will cover large areas at the same depth as Hubble,” Robertson said. “If they overlap and JWST is still operational when WFIRST launches, it will be a very powerful combination.”

    WFIRST is slated to launch in the mid-2020s. The project is managed at Goddard, with participation by the Jet Propulsion Laboratory in Pasadena, California, the Space Telescope Science Institute (STScI) in Baltimore, the Infrared Processing and Analysis Center (IPAC) in Pasadena, and a science team with members from U.S. research institutions across the country.

    See the full article here .

    Please help promote STEM in your local schools.

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    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

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