Tagged: NSF’s NOIRLab Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 5:00 pm on April 7, 2021 Permalink | Reply
    Tags: "Caught Speeding- Clocking the Fastest-Spinning Brown Dwarfs", , , , , NSF’s NOIRLab   

    From NOIRLab: “Caught Speeding- Clocking the Fastest-Spinning Brown Dwarfs” 

    NOIRLab Composite

    From NOIRLab

    7 April 2021

    Megan Tannock
    Western University (CA)
    Email: mtannock@uwo.ca

    Stanimir Metchev
    Canada Research Chair in Extrasolar Planets
    Institute for Earth and Space Exploration, Western University
    Email: smetchev@uwo.ca

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    4.7.21

    1

    Gemini North observations help set rotational speed limit for brown dwarfs.

    Astronomers at Western University (CA) have discovered the most rapidly rotating brown dwarfs known. They found three brown dwarfs that each complete a full rotation roughly once every hour. That rate is so extreme that if these “failed stars” rotated any faster, they could come close to tearing themselves apart. Identified by NASA’s Spitzer Space Telescope, the brown dwarfs were then studied by ground-based telescopes including Gemini North, which confirmed their surprisingly speedy rotation.

    National Aeronautics and Space Administration(US)/Spitzer Infrared Space Telescope(US) no longer in service. Launched in 2003 and retired on 30 January 2020.

    Three brown dwarfs have been discovered spinning faster than any other found before. Astronomers at Western University in Canada first measured the rotation speeds of these brown dwarfs using NASA’s Spitzer Space Telescope and confirmed them with follow-up observations with the Gemini North telescope on Maunakea in Hawai‘i and the Carnegie Institution for Science’s Magellan Baade telescope in Chile.

    Gemini North is one of the pair of telescopes that make up the international Gemini Observatory, a Program of NSF’s NOIRLab.

    “We seem to have come across a speed limit on the rotation of brown dwarfs,” said Megan Tannock, the Western University physics and astronomy graduate student who led the discovery. “Despite extensive searches, by our own team and others, no brown dwarfs have been found to rotate any faster. In fact, faster spins may lead to a brown dwarf tearing itself apart.”

    Brown dwarfs are, simply put, failed stars. They form like stars but are less massive and more like giant planets [1].

    Tannock and Western University astronomer Stanimir Metchev worked with international collaborators to find three rapidly rotating brown dwarfs spinning around their axes once every hour. This is approximately 10 times faster than normal [2], and about 30 percent faster than the most rapid rotations previously measured in such objects.

    The astronomers used large ground-based telescopes, Gemini North in Hawai‘i and Magellan Baade in Chile, to confirm the rapid rotations. They did this by measuring alterations in the brown dwarfs’ light caused by the Doppler effect and using a computer model to match those alterations to spin rates [3]. The researchers found that these brown dwarfs spin with speeds of about 350,000 kilometers per hour (around 220,000 miles per hour) at their equator, which is 10 times faster than Jupiter.

    “These unusual brown dwarfs are spinning at dizzying speeds,” said Sandy Leggett, an astronomer at Gemini North who studies brown dwarfs. “At about 350,000 kilometers per hour, the relatively weak gravity of the brown dwarfs is barely holding them together. This exciting discovery by the Tannock team has identified rotational limits beyond which these objects may not exist.”

    The team first identified the rapid rotation rates by using NASA’s Spitzer Space Telescope to measure how quickly the brightness of the objects varied. “Brown dwarfs, like planets with atmospheres, can have large weather storms that affect their visible brightness,” explained Metchev. “The observed brightness variations show how frequently the same storms are seen as the object spins, which reveals the brown dwarf’s spin period.”

    The team’s results will appear in an upcoming issue of The Astronomical Journal.
    Notes

    [1] There are four known giant planets in the Solar System: Jupiter, Saturn, Uranus, and Neptune.

    [2] Stars, brown dwarfs, and planets generally spin around their axis once every 10 hours or more slowly. For example, Earth spins around its axis once every 24 hours while Jupiter and Saturn take about 10 hours. The Sun spins around its axis on average every 27 days. The Sun’s rotation rate varies with latitude, with its equatorial regions completing a rotation in about 25 days and the polar regions rotating once in approximately 35 days.

    [3] As each brown dwarf rotates, light from the hemisphere turning toward us appears blueshifted while light from the hemisphere turning away from us appears redshifted because of the Doppler effect. This causes absorption lines in the brown dwarf’s spectrum to appear broadened (stretched both toward the red end of the spectrum and the blue end of the spectrum). By matching this broadening to a computer model, the astronomers determined how fast each brown dwarf is spinning.
    More information

    The team is composed of Megan Tannock (Western University), Stanimir Metchev (Western University and American Museum of Natural History), Aren Heinze (University of Hawai‘i (US)), Paulo A. Miles-Páez (European Southern Observatory (EU)), Jonathan Gagné (Planétarium Rio Tinto Alcan and University of Montréal [Université de Montréal] (CA)), Adam Burgasser (University of California, San Diego (US)), Mark S. Marley (NASA Ames Research Center (US)), Dániel Apai (University of Arizona (US)), Genaro Suárez (Western University), and Peter Plavchan (George Mason University (US)).

    NSF’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory (US)). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NOIRLab(US)NOAO Cerro Tololo Inter-American Observatory(CL) approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters.

    The NOAO-Community Science and Data Center(US), and theVera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy(US) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

    NOIRLab(US) Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing NSF NOIRLab Gemini South Telescope (US) and NSF NOIRLab NOAO Southern Astrophysical Research Telescope , altitude 2,715 m (8,907 ft).

    The NSF NOIRLab Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy(US) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

     
  • richardmitnick 8:42 pm on March 16, 2021 Permalink | Reply
    Tags: "Unrivaled View of Galaxy Messier 106", , , , NSF’s NOIRLab,   

    From NOIRLab: “Unrivaled View of Galaxy Messier 106” 

    NOIRLab composite

    From NOIRLab

    16 March 2021

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    amanda.kocz@noirlab.edu

    Striking new image of the stately spiral galaxy taken with the Nicholas U. Mayall 4-meter Telescope.

    1
    This image of the spiral galaxy Messier 106, or NGC 4258, was taken with the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab*.

    *All member sites acknowledged below.

    NOAO Mayall 4 m telescope interior


    NOIRLab NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, at Kitt Peak National Observatory, in the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft).

    Kitt Peak NOIRLab National Observatory of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft), annotated.

    A popular target for amateur astronomers, Messier 106 can also be spotted with a small telescope in the constellation Ursa Major (the Great Bear). This view captures the entire galaxy, detailing the glowing spiral arms, wisps of gas, and dust lanes at the center of Messier 106 as well as the leisurely twisting bands of stars at the galaxy’s outer edges. Two dwarf galaxies also appear in the image: NGC 4248 in the lower right and UGC 7358 in the lower left. Credit: KPNO/NOIRLab/NSF/AURA Acknowledgment: PI: M.T. Patterson (New Mexico State University) Image processing: T.A. Rector (University of Alaska Anchorage), M. Zamani & D. de Martin.
    _______________________________________________________________________________________________________________________________________________
    This celestial snapshot captures the majesty of the spiral galaxy Messier 106, also known as NGC 4258. The image is arguably the best yet captured of the entire galaxy [1]. Obtained using the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, this image shows not only the glowing spiral arms, wisps of gas, and dust lanes at the core of the galaxy but also the leisurely twisting bands of stars at its outer edges.

    A popular target for amateur astronomers, Messier 106 can be spotted with a small telescope in the constellation Canes Venatici. Messier 106 is similar in size and luminosity to our galactic neighbor the Andromeda Galaxy, but it lies 10 times farther away — more than 20 million light-years from Earth. Though the galaxy measures more than 130,000 light-years from edge to edge, the vast distance between it and the Milky Way renders Messier 106 minuscule when seen from here. Its size in the night sky — if it were visible to the naked eye — is less than that of a penny held at arm’s length!

    Despite its tranquil appearance, Messier 106 has an unusually energetic inhabitant. The supermassive black hole at the heart of the galaxy — which is about 40 million times as massive as our Sun — is particularly active. As well as consuming vast amounts of gas and dust, the spinning black hole has warped the surrounding disk of gas, churning up vast amounts of material. This process has created the bright, red streamers of gas emanating from the heart of Messier 106, visible in the center of this image.

    Accompanying Messier 106 is a pair of dwarf galaxies belonging to the same galaxy group. The loose collection of stars and dust visible in the bottom-right of this image is the small irregular galaxy NGC 4248. Another small galaxy — UGC 7356 — lies to the lower-left of Messier 106 and is dwarfed by its larger neighbor [2]. Messier 106 and its companions are framed by a variety of objects, from foreground stars to background galaxies. Stars from our own galaxy stud the image, easily identified by the criss-cross diffraction patterns surrounding them. In the background, distant galaxies litter the image, some of them visible through the tenuous disk of Messier 106.

    As well as being a striking subject for astronomical images, Messier 106 has been instrumental in measuring the scale of the Universe. Astronomers measure distances in the Universe using an interconnected chain of measurements called the cosmic distance ladder, with each rung of the ladder allowing measurements of more and more distant objects. Calibrating these measurements requires objects with a known brightness — such as pulsating stars known as Cepheid variables [3]. Measurements of the Cepheids in Messier 106 have allowed astronomers to calibrate Cepheids elsewhere in the Universe — helping them to measure the distances to other galaxies [4].

    This image was one of the last to be taken with the Mosaic camera before the installation of the Dark Energy Spectroscopic Instrument (DESI), a project of the Department of Energy’s Office of Science and Lawrence Berkeley National Laboratory.

    DOE’s Lawrence Berkeley National Laboratory(US)/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory, in the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft).

    Notes

    [1] While the Hubble Space Telescope has also released a striking image of Messier 106, Hubble’s image features the center of the galaxy and not its full extent.

    [2] The night sky is thronged with stars, galaxies, and other astronomical curiosities. To help keep track of all these objects, galaxies and other astronomical objects often have identifiers consisting of a string of letters and a number. The numbers refer to the catalog the object is listed in, such as the Uppsala General Catalogue of Galaxies (UGC) or the New General Catalogue of Nebulae and Clusters of Stars (NGC), each of which lists thousands of objects. Galaxies are often identified in several catalogs, so they typically have multiple names or designations.

    [3] Astronomical objects with a known luminosity are often referred to as “standard candles.” By comparing the intrinsic brightness of such an object with how bright it appears to be, it is possible to measure how far away the standard candle is from Earth.

    [4] Astronomers have been able to estimate the distance to M106 with great precision, allowing this galaxy to play an important role in recalibrating the period–luminosity relation for Cepheid variable stars. This relation is used to measure distances not only in our galaxy but also to other nearby galaxies.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    National Science Foundation(US)’s National Optical-Infrared Astronomy Research Laboratory(US), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, Ministry of Science, Technology, Innovation and Communications [Ministério da Ciência, Tecnolgia, Inovação e Comunicações](BR), Gemini Argentina | Argentina.gob.ar and Korea Astronomy and Space Science Institute[알림사항])(KR), Kitt Peak National Observatory(US) , Cerro Tololo Inter-American Observatory(CL) , the NOAO-Community Science and Data Center(US), and theVera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy(US) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

     
  • richardmitnick 11:28 am on October 27, 2020 Permalink | Reply
    Tags: "Astronomers are Bulging with Data", , , , , NSF’s NOIRLab   

    From NOIRLab: “Astronomers are Bulging with Data” 

    NOIRLab composite

    From NOIRLab

    27 October 2020

    Contacts

    Christian I. Johnson
    Space Telescope Science Institute
    Tel: +1 410 338-2923
    Email: chjohnson1@stsci.edu

    Michael Rich
    University of California, Los Angeles
    Email: rmr@astro.ucla.edu

    Kathy Vivas
    NSF’s NOIRLab
    Email: kathy.vivas@noirlab.edu

    Will Clarkson
    University of Michigan-Dearborn
    Email: wiclarks@umich.edu

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Tel: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    1
    DECam image of the bulge of the Milky Way
    For the first time, over 250 million stars in our galaxy’s bulge have been surveyed in near-ultraviolet, optical, and near-infrared light, opening the door for astronomers to reexamine key questions about the Milky Way’s formation and history. Using ultraviolet data, and with 450,000 individual images, the team was able to measure the chemical composition of tens of thousands of stars spanning a large area of the bulge. The vast dataset can be explored in spectacular detail in this image.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    2
    This image shows a wide-field view of the center of the Milky Way with a pull-out image of the Dark Energy Camera (DECam) at the Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab. The DECam image covers around 4 x 2 degrees (an area about 8 times as wide as the full Moon). Credit:CTIO/NOIRLab/DOE/NSF/AURA/STScI, W. Clarkson (UM-Dearborn), C. Johnson (STScI), and M. Rich (UCLA)/E.Slawik.


    Astronomers are Bulging with Data
    Credit:
    Images and videos: CTIO/NOIRLab/NSF/AURA/STScI, W. Clarkson (UM-Dearborn), C. Johnson (STScI), M. Rich (UCLA)/E.Slawik, S. Brunier/Digitized Sky Survey 2, D. Munizaga.
    Image Processing: W. Clarkson (UM-Dearborn), C. Johnson (STScI), and M. Rich (UCLA),Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.
    Music: Kevin MacLeod – Rising.

    The mysteries of the Milky Way are revealed in spectacular detail, thanks to the efforts of a team of astronomers who have observed 250 million stars in the bulge at the heart of the Milky Way using the Dark Energy Camera (DECam). DECam, primarily funded by the U.S. Department of Energy, is mounted on the Víctor M.Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile, a program of NSF’s NOIRLab. By detecting the ultraviolet light from stars in the bulge known as Red Clump stars, they were able to analyze the chemical composition of over 70,000 stars over an area of sky 1,000 times as large as the full Moon (an area larger than 20 x 10 degrees stretching over the constellations Sagittarius and Scorpius).

    The data are hosted and served to the community by NOIRLab’s Community Science and Data Center (CSDC), also a program of NSF’s NOIRLab, which handled the more than 7,000 DECam exposures, comprising more than 3.5 trillion pixels. A color-composite showing a main part of these data is shown in this image, and can be explored in all its whopping 50,000 x 25,000 pixels in this zoomable version.

    The newly published study has shown that the stars near the very center of the Milky Way have a very similar composition, which suggests that they formed at around the same time. Normally composition is measured with a spectrograph, targeting a relatively small number of stars at a time (although the revolutionary DESI instrument at Kitt Peak National Observatory, a program of NSF’s NOIRLab, will soon be able to do thousands). However, the Blanco DECam Bulge Survey took a different approach and instead precisely measured the stars’ brightness differences from ultraviolet to infrared wavelengths. These differences in brightness at different wavelengths are called photometric colors by astronomers, and can reveal the composition of stars when the dataset is calibrated with stars measured spectroscopically.

    The team used DECam’s three square degree field of view to take over 450,000 individual images, before focusing on the subsample of 70,000 stars, which is substantially larger than previous spectroscopic bulge surveys. Future work with the full DECam data set will yield millions of composition measurements, a sample size more than 200 times that of even the largest spectroscopic surveys.

    Kathy Vivas, co-author and NOIRLab astronomer said, “This is exactly the strength of the Dark Energy Camera — to undertake these kinds of studies. While it was originally aimed at the study of the distant Universe to measure its expansion, DECam has proven to be a powerful instrument to study our Milky Way as well.”

    The survey results are providing key insights into the formation of the bulge and a glimpse of what is to come when the upcoming Vera C. Rubin Observatory begins acquiring its own images of the Milky Way. “Many other spiral galaxies look like the Milky Way and have similar bulges, so if we can understand how the Milky Way formed its bulge then we’ll have a good idea of how the other galaxies did too,” said Johnson.

    These data would also surely have fascinated Víctor M. Blanco and his wife Betty Blanco, after whom the Blanco DECam Bulge Survey is named. Almost 50 years ago they used the same telescope to explore, amongst other things, the Milky Way’s bulge. Half a century later, our home galaxy has plenty of surprises to offer.
    More information

    This research was presented in two papers which appeared in the journal MNRAS.
    The Blanco DECam bulge survey. I. The survey description and early results

    Blanco DECam Bulge Survey (BDBS) II: project performance, data analysis, and early science results

    The team involved is composed of R. Michael Rich (University of California, Los Angeles), Christian I. Johnson (Space Telescope Science Institute), Michael Young (Indiana University), Iulia T. Simion (Shanghai Astronomical Observatory), William I. Clarkson (University of Michigan-Dearborn), Catherine Pilachowski (Indiana University), Scott Michael (Indiana University), Andrea Kunder (St Martin’s University), A. Katherina Vivas (NSF’s NOIRLab), Andreas Koch (University of Heidelberg), Tommaso Marchetti (European Southern Observatory), Rodrigo Ibata (Strasbourg Observatory), Nicolas Martin (Strasbourg Observatory), Annie C. Robin (University of Bourgogne Franche-Comté), Nadége Lagarde (University of Bourgogne Franche-Comté), Michelle Collins (University of Surrey), Željko Ivezic (University of Washington), Roberto de Propris (Finnish Centre for Astronomy with ESO), and Juntai Shen (Shanghai Jiao Tong University).

    See the full article here.
    See the full NASA/ESA Hubble article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

     
  • richardmitnick 10:38 am on September 22, 2020 Permalink | Reply
    Tags: "Taking Stock of Backyard Worlds", , , , , , NSF’s NOIRLab, The citizen science project Backyard Worlds: Planet 9, Y dwarfs are the coldest of substars.   

    From AAS NOVA: “Taking Stock of Backyard Worlds” 

    AASNOVA

    From AAS NOVA

    21 September 2020
    Susanna Kohler

    1
    Artist’s impression of a Y-dwarf star, which are the coldest star-like bodies known. [NASA/JPL-Caltech]

    We’ve tallied up a lot of the stars and substars that lie within our solar neighborhood, but we’re missing a key population: the coolest, dimmest substar dwarfs that lurk nearby. A citizen science study is now filling in this gap with the discovery of 95 new “backyard worlds.”

    A Gap in the Census

    2
    Three types of progressively cooler brown dwarfs and their characteristics. Y dwarfs are the coldest of substars. Credit: NASA/JPL-Caltech/Backyard Worlds.

    Stellar classification roughly tracks with star temperature, ranging from the wildly hot and bright O-type stars (which burn at more than 30,000 K) all the way down to dim brown-dwarf substars of T and Y types (which can be nearly as cool as Earth, at just 300 K).

    To better understand how stars and substars are distributed across this range, we’ve attempted to take a census of the bodies in our local solar neighborhood and observe their characteristics. The challenge in this lies on the brown-dwarf end: we’ve observed very few of the smallest, coldest substars in our solar backyard, because they’re so dim and hard to spot.

    How to Spot a Hidden Substar

    The key to finding these lurkers is all-sky surveying at long infrared wavelengths. The Wide-field Infrared Survey Explorer (WISE) is an ideal telescope for the task: this spacecraft has surveyed the entire sky in infrared 14 times over the span of a decade, providing us with a wealth of archived data.

    NASA/Wise spacecraft.

    By searching for cool, dim objects that move quickly between successive images, we can identify the nearby brown dwarfs that we’ve been missing.

    The catch? WISE’s imaging archive contains over 30 trillion pixels! Identifying small, dim, moving objects requires human eyes — a lot of them. It’s definitely time for crowd-sourcing.

    A Job for 200,000 Eyes

    The citizen science project Backyard Worlds: Planet 9 (which we’ve previously talked about) relies on more than a hundred thousand volunteers to examine WISE images and spot cool, nearby star and substar candidates — and after roughly three years of work, the project has now completed around 1.5 million classifications!

    In a recent publication, a team of scientists led by Aaron Meisner (NSF’s NOIRLab) describes the follow-up of some of the most likely nearby, cold brown dwarf candidates from Backyard Worlds with the Spitzer space telescope.


    NOIRLab.

    NASA/Spitzer Infrared telescope no longer in service.

    Discoveries in the Data

    4
    Full-sky distribution of the 96 Backyard Worlds targets followed up with Spitzer. [Meisner et al. 2020.]

    Meisner and the Backyard Worlds team used Spitzer to confirm 75 objects as newly discovered members of the solar neighborhood. Their discoveries include:

    -A number of Y-dwarf candidates. These are the coldest of substars, of which there are only a handful known.
    -Two new worlds that lie within 30 light-years of the Sun.
    -Two sources moving faster than 2” per year — a potential indicator that they’re relatively old objects with low metallicity.
    -A T-dwarf substar that appears to be in a binary with a white dwarf.

    There’s still ~1,500 more Backyard Worlds candidates to be followed up, and many of the team’s discoveries will make excellent targets for future observations and characterization. The continued exploration of these coldest substellar neighbors will help us to bridge the gap between low-mass stars and massive planets, expanding our understanding of the worlds that lurk in our solar neighborhood.

    Citation

    “Spitzer Follow-up of Extremely Cold Brown Dwarfs Discovered by the Backyard Worlds: Planet 9 Citizen Science Project,” Aaron M. Meisner et al 2020 ApJ 899 123.
    https://iopscience.iop.org/article/10.3847/1538-4357/aba633

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

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