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  • richardmitnick 2:38 pm on January 10, 2019 Permalink | Reply
    Tags: , , , , , , , NASA ESA Hubble, PHANGS-ALMA   

    From ALMA: “What 100,000 Star Factories in 74 Galaxies Tell Us about Star Formation across the Universe” 

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    From ALMA

    9 January, 2019

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Phone: +1 434 296 0314
    Cell phone: +1 202 236 6324
    Email: cblue@nrao.edu

    Calum Turner
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: calum.turner@eso.org

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    1

    Galaxies come in a wide variety of shapes and sizes. Some of the most significant differences among galaxies, however, relate to where and how they form new stars. Compelling research to explain these differences has been elusive, but that is about to change. The Atacama Large Millimeter/submillimeter Array (ALMA) is conducting an unprecedented survey of nearby disk galaxies to study their stellar nurseries. With it, astronomers are beginning to unravel the complex and as-yet poorly understood relationship between star-forming clouds and their host galaxies.

    A vast, new research project with ALMA, known as PHANGS-ALMA (Physics at High Angular Resolution in Nearby GalaxieS), delves into this question with far greater power and precision than ever before by measuring the demographics and characteristics of a staggering 100,000 individual stellar nurseries spread throughout 74 galaxies.

    PHANGS-ALMA, an unprecedented and ongoing research campaign, has already amassed a total of 750 hours of observations and given astronomers a much clearer understanding of how the cycle of star formation changes, depending on the size, age, and internal dynamics of each individual galaxy. This campaign is ten- to one-hundred-times more powerful (depending on your parameters) than any prior survey of its kind.

    “Some galaxies are furiously bursting with new stars while others have long ago used up most of their fuel for star formation. The origin of this diversity may very likely lie in the properties of the stellar nurseries themselves,” said Erik Rosolowsky, an astronomer at the University of Alberta in Canada and a co-Principal Investigator of the PHANGS-ALMA research team.

    He presented initial findings of this research at the 233rd meeting of the American Astronomical Society being held this week in Seattle, Washington. Several papers based on this campaign have also been published in The Astrophysical Journal and the Astrophysical Journal Letters [Papers are listed below].

    “Previous observations with earlier generations of radio telescopes provide some crucial insights about the nature of cold, dense stellar nurseries,” Rosolowsky said. “These observations, however, lacked the sensitivity, fine-scale resolution, and power to study the entire breadth of stellar nurseries across the full population of local galaxies. This severely limited our ability to connect the behavior or properties of individual stellar nurseries to the properties of the galaxies that they live in.”

    For decades, astronomers have speculated that there are fundamental differences in the way disk galaxies of various sizes convert hydrogen into new stars. Some astronomers theorize that larger, and generally older galaxies, are not as efficient at stellar production as their smaller cousins. The most logical explanation would be that these big galaxies have less efficient stellar nurseries. But testing this idea with observations has been difficult.

    For the first time, ALMA is allowing astronomers to conduct the necessary wide-ranging census to determine how the large-scale properties (size, motion, etc.) of a galaxy influence the cycle of star formation on the scale of individual molecular clouds. These clouds are only about a few tens to a few hundreds of light-years across, which is phenomenally small on the scale of an entire galaxy, especially when seen from millions of light-years away.

    “Stars form more efficiently in some galaxies than others, but the dearth of high-resolution, cloud-scale observations meant our theories were weakly tested, which is why these ALMA observations are so critical,” said Adam Leroy, an astronomer at The Ohio State University and co-Principal Investigator on the PHANGS-ALMA team.

    Part of the mystery of star formation, the astronomers note, has to do with the interstellar medium – all the matter and energy that fills the space between the stars.

    Astronomers understand that there is an ongoing feedback loop in and around the stellar nurseries. Within these clouds, pockets of dense gas collapse and form stars, which disrupts the interstellar medium.

    “Indeed, comparing early PHANGS observations with the locations of newly formed stars shows that the newly formed stars quickly destroy their birth clouds,” said Rosolowsky. “The PHANGS team is studying how this disruption plays out in different types of galaxies, which may be a key factor in star-forming efficiency.”

    For this research, ALMA is observing molecules of carbon monoxide (CO) from all relatively massive, generally face-on spiral galaxies visible from the Southern Hemisphere. Molecules of CO naturally emit the millimeter-wavelength light that ALMA can detect. They are particularly effective at highlighting the location of star-forming clouds.

    “ALMA is a stunningly efficient machine to map carbon monoxide over large areas in nearby galaxies,” said Leroy. “It was able to perform this survey because of the combined power of the 12-meter dishes, which study fine-scale features, and the smaller, 7-meter dishes at the center of the array, which are sensitive to large-scale features, essentially filling in the gaps.”

    A companion survey, PHANGS-MUSE, is using the Very Large Telescope to obtain optical imaging of the first 19 galaxies observed by ALMA.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo, with an elevation of 2,635 metres (8,645 ft) above sea level,

    MUSE stands for the Multi-Unit Spectroscopic Explorer.

    ESO MUSE on the VLT on Yepun (UT4)

    Another survey, PHANGS-HST uses the Hubble Space Telescope to survey 38 of these galaxies to find their youngest stellar clusters.

    NASA/ESA Hubble Telescope

    Together, these three surveys give a startlingly complete picture of how well galaxies form stars by probing cold molecular gas, its motion, the location of ionized gas (regions where stars are already forming), and the galaxies’ complete stellar populations.

    “In astronomy, we have no ability to watch the cosmos change over time; the timescales simply dwarf human existence,” noted Rosolowsky. “We can’t watch one object forever, but we can observe hundreds of thousands of star-forming clouds in galaxies of different sizes and ages to infer how galactic evolution works. That is the real value of the PHANGS-ALMA campaign.”

    “We also look at thousands to tens of thousands of star-forming regions within each galaxy, catching them across their life cycle. This lets us build a picture of the birth and death of stellar nurseries across galaxies, something almost impossible before ALMA,” added Leroy.

    So far, PHANGS-ALMA has studied about 100,000 Orion Nebula-like objects in the nearby universe. It is expected that the campaign will eventually observe around 300,000 star-forming regions.

    These results are being published in a series of papers in The Astrophysical Journal and the Astrophysical Journal Letters. Already accepted and published:

    “Cloud-scale Molecular Gas Properties in 15 Nearby Galaxies,” J. Sun, et al., 2018 June. 25, The Astrophysical Journal [http://iopscience.iop.org/article/10.3847/1538-4357/aac326]

    “Star Formation Efficiency per Free-fall Time in nearby Galaxies,” D. Utomo, et al., 2018 July 11, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8213/aacf8f/meta]

    “A 50 pc Scale View of Star Formation Efficiency across NGC 628,” K. Kreckel, et al., 2018 August 14, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8213/aad77d]

    IMAGES

    1
    Six ALMA-imaged galaxies out of a collection of the 74. The images were taken as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton

    2
    ALMA image of galaxy NGC 4321, also known as Messier 100, an intermediate spiral galaxy located about 55 million light-years from Earth in the constellation Coma Berenices. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton

    3
    ALMA image of NGC 628, also known as Messier 74, a spiral galaxy in the constellation Pisces, located approximately 32 million light-years from Earth. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton

    4
    Composite ALMA (orange) and Hubble (blue) image of NGC 628, also known as Messier 74, a spiral galaxy in the constellation Pisces, located approximately 32 million light-years from Earth. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: NRAO/AUI/NSF, B. Saxton: ALMA (ESO/NAOJ/NRAO); NASA/Hubble

    See the full article here .

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    Please help promote STEM in your local schools.

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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  • richardmitnick 9:28 pm on January 9, 2019 Permalink | Reply
    Tags: , , , , NASA ESA Hubble, NASA's Hubble Helps Astronomers Uncover the Brightest Quasar in the Early Universe, Super-bright quasar cataloged as J043947.08+163415.7   

    From NASA/ESA Hubble Telescope: “NASA’s Hubble Helps Astronomers Uncover the Brightest Quasar in the Early Universe” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    Jan 9, 2019

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Xiaohui Fan
    University of Arizona, Tucson, Arizona
    520-360-0956 (cell)
    520-626-7558 (office)
    fan@as.arizona.edu

    1
    Zoom Lens in Space Gives Hubble a Peek into the Era of Galaxy Birth

    Less than a billion years after the big bang, a monster black hole began devouring anything within its gravitational grasp. This triggered a firestorm of star formation around the black hole. A galaxy was being born. A blowtorch of energy, equivalent to the light from 600 trillion Suns, blazed across the universe. Now, 12.8 billion years later, the Hubble Space Telescope captured the beacon from this event. But Hubble astronomers needed help to spot it. The gravitational warping of space by a comparatively nearby intervening galaxy greatly amplified and distorted the quasar’s light, making it the brightest such object seen in the early universe. It offers a rare opportunity to study a zoomed-in image of how supermassive black holes accompanied star formation in the very early universe and influenced the assembly of galaxies.

    Astronomers have discovered the brightest object ever seen at a time when the universe was less than one billion years old, with the help of NASA’s Hubble Space Telescope. The brilliant beacon is a quasar, the core of a galaxy with a black hole ravenously eating material surrounding it.

    Though the quasar is very far away — 12.8 billion light-years — astronomers can detect it because a galaxy closer to Earth acts as a lens and makes the quasar look extra bright. The gravitational field of the closer galaxy warps space itself, bending and amplifying the distant quasar’s light. This effect is called gravitational lensing.

    Gravitational Lensing NASA/ESA

    Though researchers have searched for these very remote quasars for over 20 years, a rare and fortuitous celestial alignment made this one visible to them. “We don’t expect to find many quasars brighter than that in the whole observable universe,” said lead investigator Xiaohui Fan of the University of Arizona, in Tucson.

    The super-bright quasar, cataloged as J043947.08+163415.7, could hold the record of being the brightest in the early universe for some time, making it a unique object for follow-up studies.

    Shining with light equivalent to 600 trillion Suns, the quasar is fueled by a supermassive black hole at the heart of a young galaxy in the process of forming. An immense amount of energy is emitted as the black hole consumes material around it. The detection provides a rare opportunity to study a zoomed-in image of how such black holes accompanied star formation in the very early universe and influenced the assembly of galaxies.

    Besides being bright in visible and infrared wavelengths, the lensed quasar is also bright in submillimeter wavelengths, where it was observed with the James Clerk Maxwell Telescope on Mauna Kea, Hawaii.

    East Asia Observatory James Clerk Maxwell telescope, Mauna Kea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    This is due to hot dust heated by intense star formation in the galaxy hosting the lensed quasar. The formation rate is estimated to be up to 10,000 stars per year (by comparison, our Milky Way galaxy makes one star per year).

    “Clearly, this black hole is not only accreting gas, but has a lot of star formation around it,” said team member Jinyi Yang at the University of Arizona. “However, because of the boosting effect of gravitational lensing, the actual rate of star formation could be much lower than the observed brightness suggests,” she added.

    The quasar existed at a transitional period in the universe’s evolution, called reionization, where light from young galaxies and quasars reheated the obscuring hydrogen that cooled off not long after the big bang.

    The quasar would have gone undetected if not for the power of gravitational lensing, which boosted its brightness by a factor of 50.

    However, because very distant quasars are identified by their red color (due to absorption by diffuse gas in intergalactic space), sometimes their light is “contaminated,” and looks bluer because of the starlight of an intervening galaxy. As a result, they may be overlooked in quasar searches because their color is diluted to resemble that of a normal galaxy. Fan proposes that many other remote quasars have been missed due to this light contamination.

    His team got lucky with finding J043947.08+163415.7, because the quasar is so bright it drowns out the starlight from the especially faint foreground lensing galaxy. “Without this high level of magnification, it would make it impossible for us to see the galaxy,” said team member Feige Wang of the University of California, Santa Barbara. “We can even look for gas around the black hole and what the black hole may be influencing in the galaxy.”

    The object was selected by its color by combining photometric data from the United Kingdom Infrared Telescope Hemisphere Survey, the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) at optical wavelengths, and NASA’s Wide-field Infrared Survey Explorer archive in the mid-infrared.


    UKIRT, located on Mauna Kea, Hawai’i, USA as part of Mauna Kea Observatory,4,207 m (13,802 ft) above sea level

    Pann-STARSR1 Telescope, U Hawaii, Mauna Kea, Hawaii, USA, Altitude 3,052 m (10,013 ft)

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA, 4,207 m (13,802 ft) above sea level

    Follow-up spectroscopic observations were conducted by the University of Arizona’s Multi-Mirror Telescope, the Gemini Observatory and the Keck Observatory. These observations revealed the signature of a very faint foreground galaxy directly between the quasar and Earth that is magnifying the quasar image. However, because the source looks fuzzy in the ground-based observations (and so could be mistaken for only a galaxy), the researchers used Hubble’s exquisite imaging capabilities to confirm it is a lensed quasar.

    CfA U Arizona Fred Lawrence Whipple Observatory Steward Observatory MMT Telescope at the summit of Mount Hopkins near Tucson, Arizona, USA, Altitude 2,616 m (8,583 ft)


    Gemini/North telescope at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level,

    “It’s a hard system to photograph because it turns out to be so compact, which requires the sharpest view from Hubble,” Fan said.

    The quasar is ripe for future scrutiny. Fan’s team is analyzing a detailed 20-hour spectrum from the European Southern Observatory’s Very Large Telescope, which would show gas absorption features to identify chemical composition and temperatures of intergalactic gas in the early universe. Astronomers also will use the Atacama Large Millimeter/submillimeter Array, and eventually NASA’s James Webb Space Telescope, to look within 150 light-years of the black hole to directly detect the influence of the black hole’s gravity on gas motion and star formation in its vicinity.

    Fan will present the team’s results at a press conference Jan. 9, 2019, at the 233rd meeting of the American Astronomical Society in Seattle, Washington. The team’s science paper is available online in The Astrophysical Journal Letters.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 1:55 pm on January 9, 2019 Permalink | Reply
    Tags: , , , , Hubble telescope camera is broken — and US government shutdown could delay repairs, NASA ESA Hubble, Wide Field Camera 3   

    From Nature: “Hubble telescope camera is broken — and US government shutdown could delay repairs” 

    Nature Mag
    From Nature

    09 January 2019

    NASA/ESA Hubble Telescope

    Ageing telescope’s wide-field camera fails while key NASA staff are on involuntary, indefinite leave due to political impasse.

    NASA/ESA Hubble WFC3

    One of the Hubble Space Telescope’s main instruments stopped working on 8 January because of an unspecified hardware problem, NASA says. Engineers are unlikely to be able to fix the ageing telescope until the ongoing US government shutdown ends — whenever that might be.

    Hubble’s mission operations are based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, where most employees are on involuntary leave during the shutdown. A few people who operate spacecraft that are actively flying, including Hubble, have been allowed to keep working.

    But fixing the problem with Hubble, which is almost 30 years old, will almost certainly involve additional government employees who are forbidden to work during the shutdown. NASA has formed an investigative team, composed primarily of contractors and experts from its industry partners, to examine the technical troubles.

    Federal law allows agencies to keep some personnel working during a shutdown if they are deemed necessary to protect life and property. It is not clear whether NASA might request an emergency exception to allow repairs to Hubble before the shutdown — now in its 19th day — ends.

    An e-mail to a NASA press officer seeking comment prompted this automatic reply: “I am in furlough status and unable to respond to your message at this time.”

    Camera trouble

    The instrument that broke is Hubble’s Wide Field Camera 3, one of its scientific workhorses. The telescope has one other camera and two spectrographs that remain operational and will keep collecting data, NASA said in an 8 January announcement.

    In October, Hubble stopped working entirely for three weeks after the failure of one of the gyroscopes that it uses to orient itself in space. Engineers fixed the problem, but the rescue effort required input from experts from across NASA, including many who are currently furloughed.

    The Space Telescope Science Institute in Baltimore, Maryland, which runs Hubble’s science operations, remains open for now, using money it received from NASA before the shutdown started. But many of Hubble’s technical experts are based at Goddard, which is closed.

    Hubble launched in 1990 and has been upgraded and updated five times by visiting astronauts, the last time in 2009. The Wide Field Camera 3 was installed during that final servicing mission. It has a back-up set of electronics that can be used if something has gone permanently wrong with the main set — but engineers won’t know that until they are allowed to work on it.

    The risk of not being able to fix Hubble if something broke is one of the impacts scientists were worried about as the government shutdown began on 22 December.

    The shutdown, which affects roughly 75% of the government, is now in its third week with no end in sight. If it persists until 12 January, it will break the record for longest shutdown, which was set by a 21-day event that began on 16 December 1995.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Natureis a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public.

     
  • richardmitnick 2:12 pm on January 8, 2019 Permalink | Reply
    Tags: , , , , NASA ESA Hubble, Water and organic compounds essential for life as we know it may get blown away before they can reach the surface of young planets, Young Planets Orbiting Red Dwarfs May Lack Ingredients for Life   

    From NASA/ESA Hubble Telescope: “Young Planets Orbiting Red Dwarfs May Lack Ingredients for Life” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    Jan 8, 2019

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Carol Grady
    Eureka Scientific, Oakland, California
    carol.a.grady@nasa.gov

    Glenn Schneider
    Steward Observatory, Tucson, Arizona
    gschneider@as.arizona.edu

    John Wisniewski
    University of Oklahoma, Norman, Oklahoma
    wisniewski@ou.edu

    1
    AU Microscopii. Release type: American Astronomical Society Meeting.

    Rocky planets orbiting red dwarf stars may be bone dry and lifeless, according to a new study using NASA’s Hubble Space Telescope. Water and organic compounds, essential for life as we know it, may get blown away before they can reach the surface of young planets.

    This hypothesis is based on surprising observations of a rapidly eroding dust-and-gas disk encircling the young, nearby red dwarf star AU Microscopii (AU Mic) by Hubble and the European Southern Observatory’s Very Large Telescope (VLT) in Chile.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo

    Red dwarfs, which are smaller and fainter than our Sun, are the most abundant and longest-lived stars in the galaxy.

    Fast-moving blobs of material appear to be ejecting particles from the AU Mic disk. If the disk continues to dissipate at this rapid pace, it will be gone in about 1.5 million years. In that short time, icy material from comets and asteroids could be cleared out of the disk. Comets and asteroids are important because they are believed to have seeded rocky planets such as Earth with water and organic compounds, the chemical building blocks for life. If this same transport system is needed for planets in the AU Mic system, then they may end up “dry” and dusty — inhospitable for life as we know it.

    “The Earth, we know, formed ‘dry,’ with a hot, molten surface, and accreted atmospheric water and other volatiles for hundreds of millions of years, being enriched by icy material from comets and asteroids transported from the outer solar system,” said co-investigator Glenn Schneider of Steward Observatory in Tucson, Arizona.

    The observations are led by John Wisniewski of the University of Oklahoma in Norman, whose team is composed of 14 astronomers from the U.S. and Europe.

    If the activity around AU Mic is typical of the planet-birthing process among red dwarfs, it could further reduce prospects of habitable worlds across our galaxy. Previous observations suggest that a torrent of ultraviolet light from young red dwarf stars quickly strips away the atmosphere of any orbiting planets. This particular star is only 23 million years old.

    Surveys have shown that terrestrial planets are common around red dwarfs. In fact, they should contain the bulk of our galaxy’s planet population, which could number tens of billions of worlds. Planets have been found within the habitable zone of several nearby red dwarfs, but their physical characteristics are largely unknown.

    Blown Out by Blobs

    Observations by Hubble’s Space Telescope Imaging Spectrograph (STIS) and the VLT show that the AU Mic circumstellar disk is being excavated by fast-moving blobs of circumstellar material, which are acting like a snowplow by pushing small particles — possibly containing water and other volatiles — out of the system. Researchers don’t yet know how the blobs were launched. One theory is that powerful mass ejections from the turbulent star expelled them. Such energetic activity is common among young red dwarfs.

    “These observations suggest that water-bearing planets might be rare around red dwarfs because all the smaller bodies transporting water and organics are blown out as the disk is excavated,” explained Carol Grady of Eureka Scientific in Oakland, California, co-investigator on the Hubble observations.

    Conventional theory holds that billions of years ago Earth formed as a comparatively dry planet. Gravitationally perturbed asteroids and comets, rich in water from the cooler outer solar system, bombarded Earth and seeded the surface with ice and organic compounds. “However, this process may not work in all planetary systems,” Grady said.

    The team determined the disk’s lifespan by using an estimated mass of the disk from an independent study, as well as calculating the mass of the escaping blobs in their STIS visible-light data. The mass of each blob is about four ten-millionths the mass of Earth. The disk’s mass — about 1.7 times more massive than Earth — is based on data taken by the Atacama Large Millimeter/submillimeter Array (ALMA).

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Although the mass of the wayward blobs seems tiny, the diameter of each blob could stretch at least from the Sun to Jupiter. At present, the team has spotted six outbound blobs, but it is possible that there is a continuous stream of them. Groups of blobs careening through the disk could sweep out material fairly quickly.

    “The fast dissipation of the disk is not something I would have expected,” Grady said. “Based on the observations of disks around more luminous stars, we had expected disks around fainter red dwarf stars to have a longer time span. In this system, the disk will be gone before the star is 25 million years old.” She added that AU Mic likely started out with an outer rim of small icy bodies, like the Kuiper belt found within our own solar system. If the disk weren’t being eroded, it would have provided ices to any dry inner planets.

    Probing the Blob Mystery

    Hubble astronomers spotted the blobs in STIS visible-light images taken in 2010-2011. As a follow-up to the Hubble study, the SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument mounted on the European Southern Observatory’s Very Large Telescope in Chile, made near-infrared observations.

    ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT MELIPAL UT3, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

    Features in the disk were hinted at in observations taken in 2004 by ground-based telescopes and Hubble’s Advanced Camera for Surveys.

    So far, the team has uncovered blobs on the disk’s southeast side, with estimated ejection speeds between 9,000 miles per hour and 27,000 miles per hour, fast enough to escape the star’s gravitational clutches. They currently range in distance from roughly 930 million miles to more than 5.5 billion miles from the star.

    Hubble is also showing that these blobs may not just be giant balls of dusty debris. The telescope has resolved substructure in one of the blobs, including a mushroom-shaped cap above the plane of the disk itself and a complex “loop-like” structure below the disk. “These structures could yield clues to the mechanisms that drive these blobs,” Schneider said.

    The system resides 32 light-years away in the southern constellation Microscopium.

    “AU Mic is ideally placed,” Schneider said. “But it is only one of about three or four red-dwarf systems with known starlight-scattering disks of circumstellar debris. The other known systems are typically about six times farther away, so it’s challenging to conduct a detailed study of the types of features in those disks that we see in AU Mic.”

    However, astronomers are beginning to identify some possibly similar activity in these other systems. “It shows that AU Mic is not unique,” Grady said. “In fact, you could argue that because it is one of the nearest systems of this type, it would be unlikely that it would be unique.”

    The AU Mic observations show the importance of a star’s disk environment on planet formation and evolution. “What we have learned is that disks seem to be a normal part of the history of planetary systems,” Grady said. “If you don’t understand a star’s disk, you don’t have a good understanding of the resulting planetary system.”

    Grady will present the team’s results at a press conference Jan. 8, 2019, at the 233rd meeting of the American Astronomical Society in Seattle, Washington.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 5:39 pm on January 7, 2019 Permalink | Reply
    Tags: , , , , NASA ESA Hubble,   

    From NASA/ESA Hubble Telescope: “Hubble takes gigantic image of the Triangulum Galaxy” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    Mathias Jäger
    ESA/Hubble, Public Information Officer
    Garching, Germany
    Tel: +49 176 62397500
    Email: mjaeger@partner.eso.org

    1
    The sharpest view ever of the Triangulum Galaxy. Panoramic image displays nearly 25 million stars

    The NASA/ESA Hubble Space Telescope has captured the most detailed image yet of a close neighbour of the Milky Way — the Triangulum Galaxy, a spiral galaxy located at a distance of only three million light-years. This panoramic survey of the third-largest galaxy in our Local Group of galaxies provides a mesmerising view of the 40 billion stars that make up one of the most distant objects visible to the naked eye.

    Local Group. Andrew Z. Colvin 3 March 2011

    This new image of the Triangulum Galaxy — also known as Messier 33 or NGC 598 — has a staggering 665 million pixels and showcases the central region of the galaxy and its inner spiral arms. To stitch together this gigantic mosaic, Hubble’s Advanced Camera for Surveys needed to create 54 separate images.

    Under excellent dark-sky conditions, the Triangulum Galaxy can be seen with the naked eye as a faint, blurry object in the constellation of Triangulum (the Triangle), where its ethereal glow is an exciting target for amateur astronomers.

    At only three million light-years from Earth, the Triangulum Galaxy is a notable member of the Local Group — it is the group’s third-largest galaxy, but also the smallest spiral galaxy in the group [1]. It measures only about 60 000 light-years across, compared to the 200 000 light-years of the Andromdea Galaxy; the Milky Way lies between these extremes at about 100 000 light-years in diameter [2].

    Andromeda Galaxy NASA/ESA Hubble

    The Triangulum Galaxy is not only surpassed in size by the other two spirals, but by the multitude of stars they contain. The Triangulum Galaxy has at least an order of magnitude less stars than the Milky Way and two orders of magnitude less than Andromeda. These numbers are hard to grasp when already in this image 10 to 15 million individual stars are visible.

    In contrast to the two larger spirals, the Triangulum Galaxy doesn’t have a bright bulge at its centre and it also lacks a bar connecting its spiral arms to the centre. It does, however, contain a huge amount of gas and dust, giving rise to rapid star formation. New stars form at a rate of approximately one solar mass every two years.

    The abundance of gas clouds in the Triangulum Galaxy is precisely what drew astronomers to conduct this detailed survey. When stars are born, they use up material in these clouds of gas and dust, leaving less fuel for new stars to emerge. Hubble’s image shows two of the four brightest of these regions in the galaxy: NGC 595 and NGC 604. The latter is the second most luminous region of ionised hydrogen within the Local Group and it is also among the largest known star formation regions in the Local Group.

    These detailed observations of the Triangulum Galaxy have tremendous legacy value — combined with those of the Milky Way, the Andromeda Galaxy and the irregular Magellanic Cloud galaxies, they will help astronomers to better understand star formation and stellar evolution.
    Notes

    [1] Our galaxy, the Milky Way, is part of the Local Group, an assembly of more than 50 galaxies bound together by gravity. Its largest member is the Andromeda Galaxy — also known as Messier 31 — followed by the Milky Way and the Triangulum Galaxy. The remaining members of the Local Group are dwarf galaxies, each orbiting one of the three larger ones.

    [2] The much bigger Andromeda Galaxy was mapped by Hubble in 2015, creating the sharpest and largest image of this galaxy and the largest Hubble image ever (heic1502).

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:17 am on December 20, 2018 Permalink | Reply
    Tags: , , , , Faint Glow Within Galaxy Clusters Illuminates Dark Matter, Galaxy Clusters Abell S1063 and MACS J0416.1-2403, Hubble Frontier Fields, Intracluster light, , Modified Hausdorff Distance (MHD), NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “Faint Glow Within Galaxy Clusters Illuminates Dark Matter” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    Dec 20, 2018

    Leah Ramsay
    Space Telescope Science Institute, Baltimore, Maryland
    667-218-6439
    lramsay@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Mireia Montes
    University of New South Wales, Sydney, Australia
    mireia.montes.quiles@gmail.com

    1
    The eerie glow of intracluster light is demonstrated to trace the distribution of dark matter much more accurately than existing methods.
    Utilizing the powerful Hubble Frontier Fields observations of galaxy clusters, a study demonstrates that intracluster light — the light of stars orphaned in galaxy cluster mergers — aligns with dark matter, tracing its distribution more accurately than other methods. With broader use, astronomers think the technique could be a first step in exploring the nature of the unobservable, elusive dark matter that makes up the majority of the universe.

    2
    Galaxy Clusters Abell S1063 and MACS J0416.1-2403

    Tracing Diffuse Starlight in Galaxy Clusters

    Two massive galaxy clusters — Abell S1063 (left) and MACS J0416.1-2403 (right) — display a soft blue haze, called intracluster light, embedded among innumerable galaxies. The intracluster light is produced by orphan stars that no longer belong to any single galaxy, having been thrown loose during a violent galaxy interaction, and now drift freely throughout the cluster of galaxies. Astronomers have found that intracluster light closely matches with a map of mass distribution in the cluster’s overall gravitational field. This makes the blue “ghost light” a good indicator of how invisible dark matter is distributed in the cluster. Dark matter is a key missing link in our understanding of the structure and evolution of the universe. Abell S1063 and MACS J0416.1-2403 were the strongest examples of intracluster light providing a much better match to the cluster’s mass map than X-ray light, which has been used in the past to trace dark matter.

    A new look at Hubble images of galaxies could be a step toward illuminating the elusive nature of dark matter, the unobservable material that makes up the majority of the universe, according to a study published online today in the Monthly Notices of the Royal Astronomical Society.

    Utilizing Hubble’s past observations of six massive galaxy clusters in the Frontier Fields program, astronomers demonstrated that intracluster light — the diffuse glow between galaxies in a cluster — traces the path of dark matter, illuminating its distribution more accurately than existing methods that observe X-ray light.

    Intracluster light is the byproduct of interactions between galaxies that disrupt their structures; in the chaos, individual stars are thrown free of their gravitational moorings in their home galaxy to realign themselves with the gravity map of the overall cluster. This is also where the vast majority of dark matter resides. X-ray light indicates where groups of galaxies are colliding, but not the underlying structure of the cluster. This makes it a less precise tracer of dark matter.

    “The reason that intracluster light is such an excellent tracer of dark matter in a galaxy cluster is that both the dark matter and these stars forming the intracluster light are free-floating on the gravitational potential of the cluster itself—so they are following exactly the same gravity,” said Mireia Montes of the University of New South Wales in Sydney, Australia, who is co-author of the study. “We have found a new way to see the location where the dark matter should be, because you are tracing exactly the same gravitational potential. We can illuminate, with a very faint glow, the position of dark matter.”

    Montes also highlights that not only is the method accurate, but it is more efficient in that it utilizes only deep imaging, rather than the more complex, time-intensive techniques of spectroscopy. This means more clusters and objects in space can be studied in less time — meaning more potential evidence of what dark matter consists of and how it behaves.

    “This method puts us in the position to characterize, in a statistical way, the ultimate nature of dark matter,” Montes said.

    “The idea for the study was sparked while looking at the pristine Hubble Frontier Field images,” said study co-author Ignacio Trujillo of the Canary Islands Institute of Astronomy in Tenerife, Spain, who along with Montes had studied intracluster light for years. “The Hubble Frontier Fields showed intracluster light in unprecedented clarity. The images were inspiring,” Trujillo said. “Still, I did not expect the results to be so precise. The implications for future space-based research are very exciting.”

    “The astronomers used the Modified Hausdorff Distance (MHD), a metric used in shape matching, to measure the similarities between the contours of the intracluster light and the contours of the different mass maps of the clusters, which are provided as part of the data from the Hubble Frontier Fields project, housed in the Mikulski Archive for Space Telescopes (MAST). The MHD is a measure of how far two subsets are from each other. The smaller the value of MHD, the more similar the two point sets are. This analysis showed that the intracluster light distribution seen in the Hubble Frontier Fields images matched the mass distribution of the six galaxy clusters better than did X-ray emission, as derived from archived observations from Chandra X-ray Observatory’s Advanced CCD Imaging Spectrometer (ACIS).

    Beyond this initial study, Montes and Trujillo see multiple opportunities to expand their research. To start, they would like to increase the radius of observation in the original six clusters, to see if the degree of tracing accuracy holds up. Another important test of their method will be observation and analysis of additional galaxy clusters by more research teams, to add to the data set and confirm their findings.

    The astronomers also look forward to the application of the same techniques with future powerful space-based telescopes like the James Webb Space Telescope and WFIRST, which will have even more sensitive instruments for resolving faint intracluster light in the distant universe.

    NASA/ESA/CSA Webb Telescope annotated

    NASA/WFIRST

    Trujillo would like to test scaling down the method from massive galaxy clusters to single galaxies. “It would be fantastic to do this at galactic scales, for example exploring the stellar halos. In principal the same idea should work; the stars that surround the galaxy as a result of the merging activity should also be following the gravitational potential of the galaxy, illuminating the location and distribution of dark matter.”

    The Hubble Frontier Fields program was a deep imaging initiative designed to utilize the natural magnifying glass of galaxy clusters’ gravity to see the extremely distant galaxies beyond them, and thereby gain insight into the early (distant) universe and the evolution of galaxies since that time. In that study the diffuse intracluster light was an annoyance, partially obscuring the distant galaxies beyond. However, that faint glow could end up shedding significant light on one of astronomy’s great mysteries: the nature of dark matter.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 12:01 pm on December 17, 2018 Permalink | Reply
    Tags: A new Hubble Archive mirror in Europe, , , , , ESA/Hubble/JWST Science Newsletter, NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “ESA/Hubble/JWST Science Newsletter” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    Antonella Nota
    ESA HST Project Scientist, STScI
    Email: hubblenewseurope@stsci.edu

    From the desk of the ESA Hubble and JWST Project Scientist

    So many important events on the Hubble front in the last few months! First, we all are thankful that Hubble returned to normal operations, with three well functioning gyros. Gyros provide key information to the complex system that Hubble uses to point to and observe your favorite target.

    So when Gyro 2 failed on 27 October a collective sigh was heard.

    Gyro 2 had been misbehaving for several months, so its departure was not unexpected. What was unexpected, though, was Gyro 3’s strange behavior when it was brought online to complete the trio. You can read here the story, why Hubble was kept offline for several days, and how we managed to get a happy ending after all. Now that Hubble has resumed nominal operations, we are grateful to the super-dedicated operation team at Goddard Space Flight Center and at STScI, where engineers and scientists worked closely together to make sure that our favorite telescope was safe and could be returned to work as soon as possible to make new scientific discoveries. With the problem being solved Hubble is expected to still be a fully functioning and productive observatory well into 2025, to overlap a couple of years with JWST.

    At the same time as the gyro story unfolded, the Time Allocation Committee was meeting in Baltimore, to assess the medium and large proposals received in response to the Cycle 26 call. This time no small proposals were allowed, as these had already been accepted in large numbers in last summer. Read here about some highlights from the time allocation process, and the first impressions from the proposal anonymisation, which seems to have stopped the bias trend noticed in previous years. The large majority of panel members and chairs also gave very positive feedback on the ability to focus only on the science merits of each proposals.

    On the archive front, there is another reason to celebrate: the European Hubble archive at ESAC – the eHST – is now and officially a full mirror of the Hubble Archive at STScI. Read here about the successful conclusion of a tightly woven collaboration between STScI, ESAC and CADC that now delivers Hubble data from three locations, in the US, Canada and Europe.

    sci18006 — Announcement
    A new Hubble Archive mirror in Europe

    17 December 2018

    In June 2018 a new mirror of the Hubble archive at STScI was opened to the public in Europe. Hosted at the ESAC Science Data Centre (ESDC) in the European Space Astronomy Centre (ESAC) near Madrid, this represents the culmination of almost two years of effort by scientists and engineers from the ESDC, the Space Telescope Science Institute (STScI), and the Canadian Astronomy Data Centre (CADC). These three partners worked together within the Hubble Space Telescope Consolidation of Pipelines project to ensure that the Hubble archives at all three data centres share a common data model and the exact same data products. ESA’s Hubble archive has been re-engineered in order to accommodate this ultimate change with minimum impact for its users.

    As a result, ESA’s new Hubble Space Telescope Science Archive (eHST) now provides access to exactly the same data as the Mikulski Archive for Space Telescopes (MAST) at STScI. Prior versions of this archive hosted locally reprocessed data products, so from version 2.0 users can be confident that products downloaded from eHST are identical to those in MAST and at the Canadian Astronomy Data Centre (CADC). In addition, users may also benefit from the eHST’s user-friendly interface and advanced functionalities, including Virtual Observatory (VO) interoperability protocols, as well as the option to query the archive via a simple and well-documented command-line interface.

    The eHST has been developed following the common approach within the ESDC, leading to a more robust archive, easy to maintain and to extend. This allows users to exploit all the Hubble science archive data collections in many flavours, visualise the Hubble Source Catalog on top of the images and explore them more globally from a multi-wavelength point of view in ESASky.

    The current collection contains all public standard-processed data from the active Hubble instruments (ACS, COS, STIS, WFC3) and from the legacy instruments (FOC, FOS, HRS, NICMOS, WFPC, WFPC2). Access to the Hubble Source Catalogue (v2.1) is available too. Plans for the near future include extending to the eHST the splendid Hubble data treasury available for the scientific community.

    If you have any question or suggestion for how to make these data services more useful or engaging to both scientists and citizens in general, please contact the eHST helpdesk at hsthelp@sciops.esa.int.

    Finally, to the community of actively engaged Hubble users: we want to hear from you! Help us make the science newsletter most useful and informative to you! Tell us what you want to know, tell us what you like and what we can improve. For 2019, we are planning to continue covering JWST, as well as Hubble, and include more of your science. Send us your feedback at HubbleNewsEurope@stsci.edu.

    And, do enjoy a restful and peaceful holiday break.

    From the entire ESA/Hubble team, Happy Holidays to all!

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:51 am on December 13, 2018 Permalink | Reply
    Tags: , , , , GJ 3470b, Hubble Finds a Fast Evaporating Exoplanet, In Search of Missing Worlds, NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “In Search of Missing Worlds, Hubble Finds a Fast Evaporating Exoplanet” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    Dec 13, 2018

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Vincent Bourrier
    University of Geneva, Sauverny, Switzerland
    011-41-22-379-2449
    vincent.bourrier@unige.ch

    1
    Exoplanet Is Shrinking as Atmosphere Leaks Off. Artist’s Illustration of Gas Streaming from GJ 3470b

    2
    Exoplanet Radius vs. Distance from Star

    In nabbing exoplanets that are precariously close to their stars, astronomers have discovered a shortage of one type of alien world. It’s a predicted class of Neptune-sized world that orbits just a few million miles from its star, much closer than the 93-million-mile distance between Earth and the Sun. Dubbed “hot Neptunes,” these planets would have atmospheres that are heated to more than 1,700 degrees Fahrenheit (hot enough to melt silver).

    However, the mysterious hot-Neptune deficiency suggests that these planets are rare, or, they were plentiful at one time, but have since disappeared. In fact, most of the known Neptune-sized exoplanets are merely “warm,” because they orbit farther away from their star than those in the region where astronomers would expect to find hot Neptunes.

    To date, astronomers have discovered two warm Neptunes that are leaking their atmospheres into space. The most recent finding, a planet cataloged as GJ 3470b, is losing its atmosphere at a rate 100 times faster than that of the previously discovered evaporating warm Neptune, GJ 436b.

    These discoveries reinforce the idea that the hotter version of these distant worlds may be a class of transitory planet whose ultimate fate is to shrink down to the most common type of known exoplanet, mini-Neptunes — planets with heavy, hydrogen-dominated atmospheres that are larger than Earth but smaller than Neptune. Eventually, these planets may downsize even further to become super-Earths, more massive, rocky versions of Earth. If GJ 3470b continues to rapidly lose mass, in a few billion years, perhaps it, too, will dwindle to a mini-Neptune.

    Fishermen would be puzzled if they netted only big and little fish, but few medium-sized fish. Astronomers likewise have been perplexed in conducting a census of star-hugging extrasolar planets. They have found hot Jupiter-sized planets and hot super-Earths (planets no more than 1.5 times Earth’s diameter). These planets are scorching hot because they orbit very close to their star. But so-called “hot Neptunes,” whose atmospheres are heated to more than 1,700 degrees Fahrenheit, have been much harder to find. In fact, only about a handful of hot Neptunes have been found so far.

    In fact, most of the known Neptune-sized exoplanets are merely “warm,” because they orbit farther away from their star than those in the region where astronomers would expect to find hot Neptunes. The mysterious hot-Neptune deficit suggests that such alien worlds are rare, or, they were plentiful at one time, but have since disappeared.

    A few years ago astronomers using NASA’s Hubble Space Telescope found that one of the warmest known Neptunes (GJ 436b) is losing its atmosphere. The planet isn’t expected to evaporate away, but hotter Neptunes might not have been so lucky.

    Now, astronomers have used Hubble to nab a second “very warm” Neptune (GJ 3470b) that is losing its atmosphere at a rate 100 times faster than that of GJ 436b. Both planets reside about 3.7 million miles from their star. That’s one-tenth the distance between our solar system’s innermost planet, Mercury, and the Sun.

    “I think this is the first case where this is so dramatic in terms of planetary evolution,” said lead researcher Vincent Bourrier of the University of Geneva in Sauverny, Switzerland. “It’s one of the most extreme examples of a planet undergoing a major mass-loss over its lifetime. This sizable mass loss has major consequences for its evolution, and it impacts our understanding of the origin and fate of the population of exoplanets close to their stars.”

    As with the previously discovered evaporating planets, the star’s intense radiation heats the atmosphere to a point where it escapes the planet’s gravitational pull like an untethered hot air balloon. The escaping gas forms a giant cloud around the planet that dissipates into space. One reason why GJ 3470b may be evaporating faster than GJ 436b is that it is not as dense, so it is less able to gravitationally hang on to the heated atmosphere.

    What’s more, the star hosting GJ 3470b is only 2 billion years old, compared to the 4-billion- to 8-billion-year-old star that planet GJ 436b orbits. The younger star is more energetic, so it bombards the planet with more blistering radiation than GJ 436b receives. Both are red dwarf stars, which are smaller and longer-lived than our Sun.

    Uncovering two evaporating warm Neptunes reinforces the idea that the hotter version of these distant worlds may be a class of transitory planet whose ultimate fate is to shrink down to the most common type of known exoplanet, mini-Neptunes — planets with heavy, hydrogen-dominated atmospheres that are larger than Earth but smaller than Neptune. Eventually, these planets may downsize even further to become super-Earths, more massive, rocky versions of Earth.

    “The question has been, where have the hot Neptunes gone?” said Bourrier. “If we plot planetary size and distance from the star, there’s a desert, a hole, in that distribution. That’s been a puzzle. We don’t really know how much the evaporation of the atmospheres played in forming this desert. But our Hubble observations, which show a large amount of mass loss from a warm Neptune at the edge of the desert, is a direct confirmation that atmospheric escape plays a major role in forming this desert.”

    The researchers used Hubble’s Space Telescope Imaging Spectrograph to detect the ultraviolet-light signature of hydrogen in a huge cocoon surrounding the planet as it passed in front of its star. The intervening cocoon of hydrogen filters out some of the starlight. These results are interpreted as evidence of the planet’s atmosphere bleeding off into space.

    The team estimates that the planet has lost as much as 35 percent of its material over its lifetime, because it was probably losing mass at a faster rate when its red-dwarf star was younger and emitting even more radiation. If the planet continues to rapidly lose material, it will shrink down to a mini-Neptune in a few billion years.

    Hydrogen probably isn’t the only element evaporating away: it may be a tracer for other material streaming off into space. The researchers plan to use Hubble to hunt for elements heavier than hydrogen and helium that have hitched a ride with the hydrogen gas to escape the planet. “We think that the hydrogen gas could be dragging heavy elements such as carbon, which reside deeper in the atmosphere, upward and out into space,” Bourrier said.

    The observations are part of the Panchromatic Comparative Exoplanet Treasury (PanCET) survey, a Hubble program to look at 20 exoplanets, mostly hot Jupiters, in the first large-scale ultraviolet, visible, and infrared comparative study of distant worlds.

    Observing the evaporation of these two warm Neptunes is encouraging, but team members know they need to study more of them to confirm predictions. Unfortunately, there may be no other planets of this class residing close enough to Earth to observe. The problem is that hydrogen gas cannot be detected in warm Neptunes farther away than 150 light-years from Earth because it is obscured by interstellar gas. GJ 3470b resides 97 light-years away.

    However, helium is another tracer for material escaping a warm Neptune’s atmosphere. Astronomers could use Hubble and the upcoming NASA James Webb Space Telescope to search in infrared light for helium, because it is not blocked by interstellar material in space.

    “Looking for helium could expand our survey range,” Bourrier said. “Webb will have incredible sensitivity, so we would be able to detect helium escaping from smaller planets, such as mini-Neptunes.”

    The researcher’s paper will appear in the Dec. 13 issue of Astronomy and Astrophysics.

    The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 12:59 pm on December 5, 2018 Permalink | Reply
    Tags: ACS, , , , COS, , COSTAR, Hubble instrumentation history, NASA ESA Hubble, WFC3, WFPC, WFPC2   

    From JPL-Caltech: “The ‘Camera That Saved Hubble’ Turns 25” 

    NASA JPL Banner

    From JPL-Caltech

    1
    Astronaut Jeffrey Hoffman removes the Wide Field and Planetary Camera 1 (WFPC 1) during the first Hubble servicing mission (SM1), which took place in December 1993. Credit: NASA

    2
    Astronauts Jeffrey Hoffman and Story Musgrave install the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope, during SM1 in December 1993. Credit: NASA

    NASA/Hubble WFPC2. No longer in service.

    Pillars of Creation. in the Eagle Nebula, NASA, ESA, and the Hubble Heritage Team (STScI/AURA) captured with WFPC2. Image credit: NASA/ESA/STScI/J. Hester and P. Scowen (Arizona State University)

    Twenty-five years ago this week, NASA held its collective breath as seven astronauts on space shuttle Endeavour caught up with the Hubble Space Telescope 353 miles (568 kilometers) above Earth. Their mission: to fix a devastating flaw in the telescope’s primary mirror.

    About the size of a school bus, the Hubble Space Telescope has an 8-foot (2.4-meter) primary mirror. The largest optical telescope ever launched into space, where it could observe the universe free from the distorting effects of Earth’s atmosphere, Hubble had a lot riding on it. But after the first images were obtained and carefully analyzed following the telescope’s deployment on April 25, 1990, it was clear that something was wrong: The images were blurry.

    Astronomers and engineers rallied to study a variety of solutions to the problem, and NASA convened an independent committee to find the source. They all came to the same conclusion: Hubble’s primary mirror, which looks like a very shallow bowl, had been polished into the wrong shape. The error was smaller than the width of a human hair, but the effect was significant. If the error went uncorrected, Hubble would never reach its full potential.

    During the week of Dec. 6, 1993, the astronaut crew installed two pieces of hardware intended to fix the error. The Corrective Optics Space Telescope Axial Replacement (COSTAR) was designed and built by a team at NASA’s Goddard Spaceflight Center in Greenbelt, Maryland, and would correct for the mirror error in three of the five instruments on Hubble.

    NASA COSTAR

    The second instrument was the Wide Field and Planetary Camera 2 (WFPC2), designed and built at NASA’s Jet Propulsion Laboratory in Pasadena, California. WFPC2, which actually contains four cameras, would go on to produce many of Hubble’s breathtaking images, helping transform our view of the cosmos.

    The size of baby grand piano, the instrument imaged objects and events that occurred in our own solar system – such as comet Shoemaker-Levy 9’s crash into Jupiter – to the most distant cosmological images that had ever been taken in visible light. It generated breathtaking snapshots of galaxies, exploded stars and nebulae where new stars are born. During the instrument’s tenure, Hubble managers pointed the telescope at a single, black patch of sky for more than a week and found thousands of previously unseen galaxies.

    But WFPC2’s success was far from guaranteed. The instrument was built on an incredibly tight timeline, and designing it to correct the flaw was something JPL’s John Trauger, principal investigator for WFPC2, would later describe as being akin to “trying to play baseball on the side of a hill.”

    “There’s a lot of pressure when you’re building a space instrument even under normal circumstances,” said Dave Gallagher, JPL’s associate director for strategic integration, who served as integration and test manager for WFPC2. “But when you’re fixing something that will essentially make or break the reputation of the entire agency, the pressure goes through the roof.”

    A Mirror Image

    In June 1990, NASA announced that the Hubble telescope was not working as expected. WFPC2 team members say they remember that the reaction from the public and the media was often pessimistic or even incredulous. Trauger watched network news anchor Tom Brokaw begin his program that evening by saying, “The Hubble Telescope you’ve heard so much about – it’s broken.”

    “The promise of the Hubble program, the application of our best technology to push back the frontiers of astronomy, had been instantly transformed in the public eye to an icon of technical failure,” Trauger wrote in an essay in 2007.

    Trauger brought his team together to work the problem. The telescope’s primary and secondary mirrors collected light and fed it to the five onboard science instruments. The primary mirror could not be replaced and could not be returned to Earth for repairs. A solution would have to be found for each of Hubble’s instruments. The COSTAR device provided corrective optics for three of them, eliminating the need to fully replace those instruments. But the same approach wouldn’t work for the telescope’s Wide Field and Planetary Camera (WFPC), the predecessor of WFPC2.

    Trauger and his team came up with a potential solution. The primary mirror error caused light striking different parts of the mirror to come into focus at different locations, so the team had to figure out how to redirect it to the appropriate focal point. Their solution was to reverse-engineer the problem: They would place four identical nickel-sized mirrors inside the instrument – one for each of the four cameras inside WFPC2 – with the same error as the flawed primary mirror, but where the primary mirror was too flat, the new mirrors would be curved too deeply. Together, these two errors would cancel each other, producing the equivalent of a single mirror with the correct shape.

    NASA accepted JPL’s proposal to build a WFPC replacement. The agency had planned to carry out Hubble repair missions every three years and decided to maintain this schedule. The first repair mission was set for the fall of 1993. JPL would need to deliver the replacement by the winter of 1992 – just over 2 years away. The race to repair Hubble was on.

    Under Pressure

    Two years was nowhere near enough time to build a new camera instrument from scratch. Thankfully, WFPC2 was already under construction at JPL; NASA had intended to eventually use it as an upgrade for WFPC or a replacement if the instrument ever failed.

    Even with work on WFPC2 already under way, the deadline required an accelerated schedule. Dave Rodgers and Larry Simmons, the WFPC2 project managers, held daily meetings with the leaders of each of WFPC2’s several components to help stay on target.

    “The daily meetings kept the pressure on all of us, all the time,” said Simmons, who retired from JPL in 2005. “We knew we only had a few years, and we had to get it done.”

    While the corrective mirrors were small, they affected nearly every step of the building process and created “an endless string of novel problems,” according to Trauger.

    To minimize the chance for error during WFPC2’s installation in low-Earth orbit, the seven astronauts who were scheduled to execute the repair mission traveled to JPL to learn about the instrument and be trained on how to install it. They would be inserting WFPC2 into a cavity in the telescope’s body, as if sliding it in a drawer. And although they would need to make sure that the electrical connections at the back of the instrument were secure, they had no way of reaching those connections; they could control only how they inserted the instrument.

    Complicating matters further was the weight of WFPC2: At more than 600 pounds (272 kilograms), it was unwieldy even in the microgravity of low-Earth orbit. One of the instrument’s mirrors, called the pickoff mirror, was mounted on a short arm located outside the protective casing. Merely bumping the mirror would misalign the system and essentially ruin the entire instrument. During WFPC2’s construction, Trauger and colleagues showed a model of the instrument to an astronaut, who bumped the pickoff mirror. Trauger couldn’t help but wonder, “Is this an omen?”

    Time to Fly

    The leaders of the WFPC2 team traveled to NASA’s Kennedy Space Center in Florida for the early morning launch on Dec. 2, 1993. After departing Kennedy and seeking out an early breakfast, Gallagher remembers looking up at the predawn sky to see the space shuttle passing overhead and nearing Hubble; the objects appeared as two faint points of light in the sky as they orbited Earth.

    On the sixth day of the mission, astronauts Jeffrey Hoffman and Story Musgrave conducted a spacewalk to remove WFPC from Hubble and install WFPC2. Everything seemed to go as planned, but the real test was yet to come.

    The astronauts returned to Earth on Dec. 13, and the first raw data from WFPC2 came back on Dec. 18. The team put the data through the image-processing software and watched anxiously as the pictures began to ratchet across the screen. There was instant relief.

    “They were sharp,” Trauger said of the images. “And it wasn’t just that we had pictures that looked amazing, it was that we were making new discoveries right away. There were things in the images that we’d never seen before.”

    NASA released those first images to the public on Jan. 13, 1994. The next day, the WFPC2 team presented the results to an overflow audience at the winter meeting of the American Astronomical Society.

    “When we showed the first images, the room erupted; we got a standing ovation,” Trauger said. “You don’t usually see that at an astronomy meeting!”

    The WFPC2 instrument operated on Hubble for over 15 years and took more than 135,000 observations of the universe. More than 3,500 science papers were written based on that data before the instrument was retired in 2009, and over 2,000 more have been published since.

    “WFPC2 didn’t succeed by magic or luck; it succeeded because we had a competent and hardworking group of people who understood what was at stake and stepped up to the challenge,” Gallagher said. “And just like with every project, I wish I could have transported that team with me to the next mission.”

    In May of 2009, astronauts removed WFPC2 from Hubble and replaced it with the Wide Field Camera 3 (WFC3), which continues to operate today – 28 years after Hubble first switched on. WFPC2 was later placed on public display at the Smithsonian Air and Space Museum in Washington, D.C.

    NASA/ESA Hubble WFC3

    When the final first-generation instrument, FOC, was replaced by the Advanced Camera for Surveys (ACS) during Servicing Mission 3B, COSTAR was no longer needed.

    NASA Hubble Advanced Camera forSurveys

    COSTAR was removed and returned to Earth during Servicing Mission 4. Its instrument bay was then reused by COS, the Cosmic Origins Spectrograph.

    NASA Hubble Cosmic Origins Spectrograph

    COSTAR is now on display at the Smithsonian National Air and Space Museum in Washington DC.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 1:10 pm on December 4, 2018 Permalink | Reply
    Tags: , , , Celebratory Galaxy Photo Honors 25th Anniversary of NASA's First Hubble Servicing Mission, , NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “Celebratory Galaxy Photo Honors 25th Anniversary of NASA’s First Hubble Servicing Mission” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    12.4.2018

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    1
    Portrait of Spiral Galaxy Messier 100 Demonstrated Hubble’s Optical Repair

    Over the past 28 years Hubble has photographed innumerable galaxies throughout the universe, near and far. But one especially photogenic galaxy located 55 million light-years away holds a special place in Hubble history. As NASA made plans to correct Hubble’s blurry vision in 1993 (due to a manufacturing flaw in its primary mirror) they selected several astronomical objects that Hubble should be aimed at to demonstrate the planned optical fix. The magnificent grand spiral galaxy Messier 100 seemed an ideal target that would just fit inside Hubble’s field-of-view. This required that a comparison photo be taken while Hubble was still bleary-eyed. The Wide Field/Planetary Camera 1 was selected for the task. And, the picture had to be taken before astronauts swapped-out the camera with the vision-corrected Wide Field/Planetary Camera 2, in December 1993.

    3

    Following the servicing mission Hubble re-photographed the galaxy again, and it snapped into crystal clear focus. The public celebrated with Hubble’s triumphant return to the clear vision that had been promised. And, jaw-dropping pictures of the vast universe that followed have not disappointed space enthusiasts. Because of the astronaut servicing missions, Hubble’s capabilities have only gotten better. To commemorate the 25th anniversary of the first servicing mission, this 2-panel photo compares the blurry, pre-servicing 1993 image to a 2009 image taken with Hubble’s newer, Wide Field Camera 3 instrument, installed during the last astronaut servicing mission to the space telescope.

    6

    4
    On the right is part of the first image taken with NASA’s Hubble Space Telescope’s (HST) Wide Field/Planetary Camera. It is shown with a ground-based picture from Las Campanas, Chile, Observatory of the same region of the sky. The Las Campanas picture was taken with a 100-inch telescope and its typical of high quality pictures obtained from the ground. All objects seen are stars within the Milky Way galaxy.

    The images of the stars in the ground-based picture are fuzzy and in some cases are overlapping, because of smearing by the Earth’s atmosphere. The same stars in the HST frame are sharper and well resolved, as shown by the double star at the top of the image. By avoiding the Earth’s atmosphere, the HST gives sharper images and better resolution. In this early engineering picture, the HST images are roughly 50 percent sharper than the ground-based images.

    Technical Details: The first image taken with the HST is intended to assist in focusing the telescope. The region observed is centered on the 8.2 magnitude star HD96755 in the open cluster NGC 3532, in the southern constellation Carina. Identical small subsections of the HST and ground-based image pictures were chosen to highlight the difference in resolution. The field shown is approximately 11 x 14 arcseconds in size and does not contain HD96755.

    The ground-based image was taken by Dr. Eric Persson at the Las Campanas Observatory in Chile, using the 100-inch DuPont reflector. We thank the Observatories of the Carnegie Institution of Washington for permission to use this picture. The three-second integration was made with a single Texas Instruments charge-coupled device (CCD) of the type used on HST. A broadband visual filter equivalent to the HST filter was used. The small field shown was extracted from an observed area covering 130 arcseconds on a side.

    The HST image is a thirty-second exposure taken by the Wide Field/Planetary Camera. The picture shown was extracted from the area observed by the WF-3 OCD using the F555W broadband filter. The measured width of star profiles (FWFM) gives a good indication of the angular resolution. For the Las Campanas picture, the FWFM is 1.1 arcseconds, typical of exposures from the best ground observations. The FWFM of the stars in the HST picture is about 0.8 arcseconds, which points out the remarkable increase in resolution of the HST even at this early stage of the focusing task.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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