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  • richardmitnick 1:54 pm on December 30, 2019 Permalink | Reply
    Tags: "These Are The Most Distant Astronomical Objects In The Known Universe", , , , , , , , , , , NASA/ESA/CSA Webb, Our most distant “standard candle” for probing the Universe is SN UDS10Wil located 17 billion light-years (Gly), , , ,   

    From Ethan Siegel: “These Are The Most Distant Astronomical Objects In The Known Universe” 

    From Ethan Siegel
    Dec 30, 2019

    Astronomy’s enduring quest is to go farther, fainter, and more detailed than ever before. Here’s the edge of the cosmic frontier.

    1
    The distant galaxy MACS1149-JD1 is gravitationally lensed by a foreground cluster, allowing it to be imaged at high resolution and in multiple instruments, even without next-generation technology.

    Gravitational Lensing NASA/ESA

    This galaxy’s light comes to us from 530 million years after the Big Bang, but the stars within it are at least 280 million years old. It is the second-most distant galaxy with a spectroscopically confirmed distance, placing it 30.7 billion light-years away from us. (ALMA (ESO/NAOJ/NRAO), NASA/ESA HUBBLE SPACE TELESCOPE, W. ZHENG (JHU), M. POSTMAN (STSCI), THE CLASH TEAM, HASHIMOTO ET AL.)

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

    NASA/ESA Hubble Telescope

    Astronomers have always sought to push back the viewable distance frontiers.

    2
    Although there are magnified, ultra-distant, very red and even infrared galaxies in the eXtreme Deep Field, there are galaxies that are even more distant out there than what we’ve discovered in our deepest-to-date views. These galaxies will always remain visible to us, but we will never see them as they are today: 13.8 billion years after the Big Bang. (NASA, ESA, R. BOUWENS AND G. ILLINGWORTH (UC, SANTA CRUZ))

    More distant galaxies appear fainter, smaller, bluer, and less evolved overall.

    3
    Galaxies comparable to the present-day Milky Way are numerous, but younger galaxies that are Milky Way-like are inherently smaller, bluer, more chaotic, and richer in gas in general than the galaxies we see today. For the first galaxies of all, this ought to be taken to the extreme, and remains valid as far back as we’ve ever seen. The exceptions, when we encounter them, are both puzzling and rare. (NASA AND ESA)

    Milky Way NASA/JPL-Caltech /ESO R. Hurt. The bar is visible in this image

    Laniakea supercluster. From Nature The Laniakea supercluster of galaxies R. Brent Tully, Hélène Courtois, Yehuda Hoffman & Daniel Pomarède at http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html. Milky Way is the red dot.

    Individual planets and stars are only known relatively nearby, as our tools cannot take us farther.

    Local Group. Andrew Z. Colvin 3 March 2011

    4
    A massive cluster (left) magnified a distant star known as Icarus more than 2,000 times, making it visible from Earth (lower right) even though it is 9 billion light years away, far too distant to be seen individually with current telescopes. It was not visible in 2011 (upper right). The brightening leads us to believe that this was a blue supergiant star, formally named MACS J1149 Lensed Star 1. (NASA, ESA, AND P. KELLY (UNIVERSITY OF MINNESOTA))

    As the 2010s end, here are our presently known most distant astronomical objects.

    4
    The ultra-distant supernova SN UDS10Wil, shown here, is the farthest type Ia supernova ever discovered, whose light arrives today from a position 17 billion light-years away.

    A white dwarf fed by a normal star reaches the critical mass and explodes as a type Ia supernova. Credit: NASA/CXC/M Weiss

    Type Ia supernovae are used as distance indicators because of their standard intrinsic brightnesses, and are some of our strongest evidence for the accelerated expansion best explained by dark energy.

    Standard Candles to measure age and distance of the universe from supernovae NASA

    (NASA, ESA, A. RIESS (STSCI AND JHU), AND D. JONES AND S. RODNEY (JHU))

    The farthest type Ia supernova, our most distant “standard candle” for probing the Universe, is SN UDS10Wil, located 17 billion light-years (Gly) away.

    4
    This illustration of superluminous supernova SN 1000+0216, the most distant supernova ever observed at a redshift of z=3.90, from when the Universe was just 1.6 billion years old, is the current record-holder for individual supernovae. Unlike SN UDS10Wil, this supernova is a Type II (core collapse) supernova, and may have formed via the pair instability mechanism, which would explain its extraordinarily large intrinsic brightness. (ADRIAN MALEC AND MARIE MARTIG (SWINBURNE UNIVERSITY))

    The most distant supernova of all, 2012’s superluminous SN 1000+0216, occurred 23 Gly away.

    6
    The most distant X-ray jet in the Universe, from quasar GB 1428, sends us light from when the Universe was a mere 1.25 billion years old: less than 10% its current age. This jet comes from electrons heating CMB photons, and is over 230,000 light-years in extent: approximately double the size of the Milky Way. (X-RAY: NASA/CXC/NRC/C.CHEUNG ET AL; OPTICAL: NASA/STSCI; RADIO: NSF/NRAO/VLA)

    NASA/Chandra X-ray Telescope

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    The most distant quasar jet, revealed by GB 1428+4217’s X-rays, is 25.4 Gly distant.

    7
    This image of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, was created from images taken from surveys made by both the Sloan Digital Sky Survey and the UKIRT Infrared Deep Sky Survey.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft)


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

    The quasar appears as a faint red dot close to the centre. This quasar was the most distant one known from 2011 until 2017, and is seen as it was just 745 million years after the Big Bang. It is the most distant quasar with a visual image available to be viewed by the public. (ESO/UKIDSS/SDSS)

    The first discovered object whose light exceeds 13 billion years in age, quasar ULAS J1120+0641, is 28.8 Gly away.

    9
    This artist’s concept shows the most distant quasar and the most distant supermassive black hole powering it. At a redshift of 7.54, ULAS J1342+0928 corresponds to a distance of some 29.32 billion light-years; it is the most distant quasar/supermassive black hole ever discovered. Its light arrives at our eyes today, in the radio part of the spectrum, because it was emitted just 686 million years after the Big Bang. (ROBIN DIENEL/CARNEGIE INSTITUTION FOR SCIENCE)

    However, quasar ULAS J1342+0928 is even farther at 29.32 Gly: our most distant black hole.

    10
    This illustration of the most distant gamma-ray burst ever detected, GRB 090423, is thought to be typical of most fast gamma-ray bursts. When one or two objects violently form a black hole, such as from a neutron star merger, a brief burst of gamma rays followed by an infrared afterglow (when we’re lucky) allows us to learn more about these events. The gamma rays from this event lasted just 10 seconds, but Nial Tanvir and his team found an infrared afterglow using the UKIRT telescope just 20 minutes after the burst, allowing them to determine a redshift (z=8.2) and distance (29.96 billion light-years) to great precision. (ESO/A. ROQUETTE)

    Gamma-ray bursts exceed even that; GRB 090423’s verified light comes from 29.96 Gly away in the distant Universe, while GRB 090429B might’ve been even farther.

    9
    Here, candidate galaxy UDFj-39546284 appears very faint and red, and from the colors it displays, it has an inferred redshift of 10, giving it an age below 500 million years and a distance greater than 31 billion light-years. Without spectroscopic confirmation, however, this and similar galaxies cannot reliably be said to have a known distance; more data is needed, as photometric redshifts are notoriously unreliable. (NASA, ESA, G. ILLINGWORTH (UNIVERSITY OF CALIFORNIA, SANTA CRUZ), R. BOUWENS (UNIVERSITY OF CALIFORNIA, SANTA CRUZ, AND LEIDEN UNIVERSITY) AND THE HUDF09 TEAM)

    Ultra-distant galaxy candidates abound, including SPT0615-JD, MACS0647-JD, and UDFj-39546284, all lacking spectroscopic confirmation.

    11
    The most distant galaxy ever discovered in the known Universe, GN-z11, has its light come to us from 13.4 billion years ago: when the Universe was only 3% its current age: 407 million years old. The distance from this galaxy to us, taking the expanding Universe into account, is an incredible 32.1 billion light-years. (NASA, ESA, AND G. BACON (STSCI))

    The most distant galaxy of all is GN-z11, located 32.1 Gly away.

    11
    The James Webb Space Telescope vs. Hubble in size (main) and vs. an array of other telescopes (inset) in terms of wavelength and sensitivity. It should be able to see the truly first galaxies, even the ones that no other observatory can see. Its power is truly unprecedented. (NASA / JWST SCIENCE TEAM)

    NASA/ESA/CSA Webb Telescope annotated

    With the 2020s promising revolutionary new observatories, these records may all soon fall.

    12
    Our deepest galaxy surveys can reveal objects tens of billions of light years away, but there are more galaxies within the observable Universe we still have yet to reveal between the most distant galaxies and the cosmic microwave background [CMB], including the very first stars and galaxies of all.

    CMB per ESA/Planck

    It is possible that the coming generation of telescopes will break all of our current distance records. (SLOAN DIGITAL SKY SURVEY (SDSS))

    See the full article here .

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    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 11:19 am on December 2, 2019 Permalink | Reply
    Tags: "Astronomers Propose a Novel Method of Finding Atmospheres on Rocky Worlds", , , , , , NASA/ESA/CSA Webb   

    From NASA/James Webb Space Telescope: “Astronomers Propose a Novel Method of Finding Atmospheres on Rocky Worlds” 

    NASA Webb Header

    NASA/ESA/CSA Webb Telescope annotated

    From NASA/James Webb Space Telescope

    December 02, 2019

    Christine Pulliam
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4366
    cpulliam@stsci.edu

    Webb Telescope Could Detect Heat Signature in a Matter of Hours, They Calculate.

    Rocky planets orbiting red dwarf stars are appealing targets for astronomers since they are both common and easier to study than other planet varieties. One long-standing question is whether such planets can host atmospheres, since they experience a harsh environment of stellar flares and particle winds.

    A team of astronomers calculates that NASA’s upcoming James Webb Space Telescope could potentially detect signs of an atmosphere in just a few hours of observing time. Since the presence of an atmosphere would lower the observed temperature of the planet’s dayside, relative to bare rock, a world with an atmosphere would have a distinct heat signature.

    Although the technique works best for planets too hot to be in the habitable zone, it could have important implications for habitable-zone worlds. If astronomers find that hot, rocky planets can preserve an atmosphere, then cooler planets should be able to as well.

    1
    Illustration of a Cloudy Exoplanet

    When NASA’s James Webb Space Telescope launches in 2021, one of its most anticipated contributions to astronomy will be the study of exoplanets—planets orbiting distant stars. Among the most pressing questions in exoplanet science is: Can a small, rocky exoplanet orbiting close to a red dwarf star hold onto an atmosphere?

    In a series of four papers in The Astrophysical Journal, a team of astronomers proposes a new method of using Webb to determine whether a rocky exoplanet has an atmosphere. The technique, which involves measuring the planet’s temperature as it passes behind its star and then comes back into view, is significantly faster than more traditional methods of atmospheric detection like transmission spectroscopy.

    https://arxiv.org/abs/1907.13138 “Identifying Candidate Atmospheres on Rocky M dwarf Planets via Eclipse Photometry”
    https://arxiv.org/abs/1907.13150 “Identifying Atmospheres on Rocky Exoplanets Through Inferred High Albedo”
    https://arxiv.org/abs/1907.13135 “Identifying Candidate Atmospheres on Rocky M dwarf Planets via Eclipse Photometry”
    https://arxiv.org/abs/1907.13145 “A Scaling Theory for Atmospheric Heat Redistribution on Rocky Exoplanets”
    “We find that Webb could easily infer the presence or absence of an atmosphere around a dozen known rocky exoplanets with less than 10 hours of observing time per planet,” said Jacob Bean of the University of Chicago, a co-author on three of the papers.

    Astronomers are particularly interested in exoplanets orbiting red dwarf stars for a number of reasons. These stars, which are smaller and cooler than the Sun, are the most common type of star in our galaxy. Also, because a red dwarf is small, a planet passing in front of it will appear to block a larger fraction of the star’s light than if the star were larger, like our Sun. This makes the planet orbiting a red dwarf easier to detect through this “transit” technique.

    Red dwarfs also produce a lot less heat than our Sun, so to enjoy habitable temperatures, a planet would need to orbit quite close to a red dwarf star. In fact, to be in the habitable zone — the area around the star where liquid water could exist on a planet’s surface — the planet has to orbit much closer to the star than Mercury is to the Sun. As a result, it will transit the star more frequently, making repeated observations easier.

    But a planet orbiting so close to a red dwarf is subjected to harsh conditions. Young red dwarfs are very active, blasting out huge flares and plasma eruptions. The star also emits a strong wind of charged particles. All of these effects could potentially scour away a planet’s atmosphere, leaving behind a bare rock.

    “Atmospheric loss is the number one existential threat to the habitability of planets,” said Bean.

    Another key characteristic of exoplanets orbiting close to red dwarfs is central to the new technique: They are expected to be tidally locked, meaning they have a permanent dayside and nightside. As a result, we see different phases of the planet at different points in its orbit. When it crosses the face of the star, we see only the planet’s nightside. But when it is about to cross behind the star (an event known as a secondary eclipse), or is just emerging from behind the star, we can observe the dayside.

    If a rocky exoplanet lacks an atmosphere, its dayside would be very hot, just as we see with the Moon or Mercury. However if a rocky exoplanet has an atmosphere, the presence of that atmosphere is expected to lower the dayside temperature that Webb would measure. It could do this in two ways. A thick atmosphere could transport heat from the dayside to the nightside through winds. A thinner atmosphere could still host clouds, which reflect a portion of the incoming starlight thereby lowering the temperature of the planet’s dayside.

    “Whenever you add an atmosphere, you’re going to lower the temperature of the dayside. So if we see something cooler than bare rock, we would infer it’s likely a sign of an atmosphere,” explained Daniel Koll of the Massachusetts Institute of Technology (MIT), the lead author on two of the papers.

    Webb is ideally suited for making these measurements because it has a much larger mirror than other telescopes such as NASA’s Hubble or Spitzer space telescopes, which allows it to collect more light, and it can target the appropriate infrared wavelengths.

    The team’s calculations show that Webb should be able to detect the heat signature of a planet’s atmosphere in one to two secondary eclipses – just a few hours of observing time. In contrast, detecting an atmosphere through spectroscopic observations would typically require eight or more transits for these same planets.

    Transmission spectroscopy, which studies starlight filtered through the planet’s atmosphere, also suffers from interference due to clouds or hazes, which can mask the molecular signatures of the atmosphere. In that case the spectral plot, rather than showing pronounced absorption lines due to molecules, would be essentially flat.

    “In transmission spectroscopy, if you get a flat line, it doesn’t tell you anything. The flat line could mean the universe is full of dead planets that don’t have an atmosphere, or that the universe is full of planets that have a whole range of diverse, interesting atmospheres, but they all look the same to us because they’re cloudy,” said Eliza Kempton of the University of Maryland, a co-author on three of the papers.

    “Exoplanet atmospheres without clouds and hazes are like unicorns – we just haven’t seen them yet, and they may not exist at all,” she added.

    The team emphasized that a cooler than expected dayside temperature would be an important clue, but it would not absolutely confirm an atmosphere exists. Any remaining doubts about the presence of an atmosphere can be ruled out with follow-up studies using other methods like transmission spectroscopy.

    The new technique’s true strength will be in determining what fraction of rocky exoplanets likely have an atmosphere. Approximately a dozen exoplanets that are good candidates for this method were detected during the past year. More are likely to be found by the time Webb is operational.

    “The Transiting Exoplanet Survey Satellite, or TESS, is finding piles of these planets,” stated Kempton.

    NASA/MIT TESS replaced Kepler in search for exoplanets

    The secondary eclipse method has one key limitation: it works best on planets that are too hot to be located in the habitable zone. However, determining whether or not these hot planets host atmospheres holds important implications for habitable-zone planets.

    “If hot planets can hold onto an atmosphere, cooler ones should be able to at least as well,” said Koll.

    The James Webb Space Telescope will be the world’s premier space science observatory when it launches in 2021.

    See the full article here .

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    The James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for later in the decade.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.

    NASA Webb NIRCam

    NASA Webb NIRspec

    NASA Webb MIRI

    CSA Webb Fine Guidance Sensor-Near InfraRed Imager and Slitless Spectrograph FGS/NIRISS


    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

    NASA image

    ESA50 Logo large

    Canadian Space Agency

     
  • richardmitnick 8:39 am on August 21, 2019 Permalink | Reply
    Tags: , , , , NASA/ESA/CSA Webb, ,   

    From University of Washington: “James Webb Space Telescope could begin learning about TRAPPIST-1 atmospheres in a single year, study indicates” 

    U Washington

    From University of Washington

    August 13, 2019
    Peter Kelley

    New research from astronomers at the University of Washington uses the intriguing TRAPPIST-1 planetary system as a kind of laboratory to model not the planets themselves, but how the coming James Webb Space Telescope might detect and study their atmospheres, on the path toward looking for life beyond Earth.

    1
    New research from UW astronomers models how telescopes such as the James Webb Space Telescope will be able to study the planets of the intriguing TRAPPIST-1 system.NASA

    NASA/ESA/CSA Webb Telescope annotated

    The study, led by Jacob Lustig-Yaeger, a UW doctoral student in astronomy, finds that the James Webb telescope, set to launch in 2021, might be able to learn key information about the atmospheres of the TRAPPIST-1 worlds even in its first year of operation, unless — as an old song goes — clouds get in the way.

    “The Webb telescope has been built, and we have an idea how it will operate,” said Lustig-Yaeger. “We used computer modeling to determine the most efficient way to use the telescope to answer the most basic question we’ll want to ask, which is: Are there even atmospheres on these planets, or not?”

    His paper, “The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST,” was published online in June in The Astronomical Journal.

    The TRAPPIST-1 system, 39 light-years — or about 235 trillion miles — away in the constellation of Aquarius, interests astronomers because of its seven orbiting rocky, or Earth-like, planets. Three of these worlds are in the star’s habitable zone — that swath of space around a star that is just right to allow liquid water on the surface of a rocky planet, thus giving life a chance.

    The star, TRAPPIST-1, was much hotter when it formed than it is now, which would have subjected all seven planets to ocean, ice and atmospheric loss in the past.

    “There is a big question in the field right now whether these planets even have atmospheres, especially the innermost planets,” Lustig-Yaeger said. “Once we have confirmed that there are atmospheres, then what can we learn about each planet’s atmosphere — the molecules that make it up?”

    Given the way he suggests the James Webb Space Telescope might search, it could learn a lot in fairly short time, this paper finds.

    Astronomers detect exoplanets when they pass in front of or “transit” their host star, resulting in a measurable dimming of starlight.

    Planet transit. NASA/Ames

    Planets closer to their star transit more frequently and so are somewhat easier to study. When a planet transits its star, a bit of the star’s light passes through the planet’s atmosphere, with which astronomers can learn about the molecular composition of the atmosphere.

    Lustig-Yaeger said astronomers can see tiny differences in the planet’s size when they look in different colors, or wavelengths, of light.

    “This happens because the gases in the planet’s atmosphere absorb light only at very specific colors. Since each gas has a unique ‘spectral fingerprint,’ we can identify them and begin to piece together the composition of the exoplanet’s atmosphere.”

    Lustig-Yaeger said the team’s modeling indicates that the James Webb telescope, using a versatile onboard tool called the Near-Infrared Spectrograph, could detect the atmospheres of all seven TRAPPIST-1 planets in 10 or fewer transits — if they have cloud-free atmospheres. And of course we don’t know whether or not they have clouds.

    If the TRAPPIST-1 planets have thick, globally enshrouding clouds like Venus does, detecting atmospheres might take up to 30 transits.

    “But that is still an achievable goal,” he said. “It means that even in the case of realistic high-altitude clouds, the James Webb telescope will still be capable of detecting the presence of atmospheres — which before our paper was not known.”

    Many rocky exoplanets have been discovered in recent years, but astronomers have not yet detected their atmospheres. The modeling in this study, Lustig-Yaeger said, “demonstrates that, for this TRAPPIST-1 system, detecting terrestrial exoplanet atmospheres is on the horizon with the James Webb Space Telescope — perhaps well within its primary five-year mission.”

    The team found that the Webb telescope may be able to detect signs that the TRAPPIST-1 planets lost large amounts of water in the past, when the star was much hotter. This could leave instances where abiotically produced oxygen — not representative of life — fills an exoplanet atmosphere, which could give a sort of “false positive” for life. If this is the case with TRAPPIST-1 planets, the Webb telescope may be able to detect those as well.

    Lustig-Yaeger’s co-authors, both with the UW, are astronomy professor Victoria Meadows, who is also principal investigator for the UW-based Virtual Planetary Laboratory; and astronomy doctoral student Andrew Lincowski. The work follows, in part, on previous work by Lincowski modeling possible climates for the seven TRAPPIST-1 worlds.

    “By doing this study, we have looked at: What are the best-case scenarios for the James Webb Space Telescope? What is it going to be capable of doing? Because there are definitely going to be more Earth-sized planets found before it launches in 2021.”

    The research was funded by a grant from the NASA Astrobiology Program’s Virtual Planetary Laboratory team, as part of the Nexus for Exoplanet System Science (NExSS) research coordination network.

    Lustig-Yaeger added: “It’s hard to conceive in theory of a planetary system better suited for James Webb than TRAPPIST-1.”

    See the full article here .


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    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 2:41 pm on May 29, 2019 Permalink | Reply
    Tags: , , , , , Infrared vision, , NASA/ESA/CSA Webb   

    Fom James Webb Space Telescope: “A New View of Exoplanets With NASA’s Upcoming Webb Telescope” 

    NASA Webb Header

    NASA Webb Telescope
    NASA/ESA/CSA

    Fom James Webb Space Telescope

    May 29, 2019

    Contact:
    Ann Jenkins /
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4488 /
    jenkins@stsci.edu

    Christine Pulliam
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4366
    cpulliam@stsci.edu

    1
    About This Image

    One of the targets Webb will study is the well-known, giant ring of dust and planetesimals orbiting a young star called HR 4796A. This Hubble Space Telescope photo shows a vast, complex dust structure, about 150 billion miles across, enveloping the young star HR 4796A. (The light from HR 4796A and its binary companion, HR 4796B, have been blocked to reveal the much dimmer dust structure.) A bright, narrow inner ring of dust encircling the star may have been corralled by the gravitational pull of an unseen giant planet. Credits: NASA/ESA and G. Schneider (University of Arizona)

    How Do We Find Exoplanets?

    The James Webb Space Telescope will open a new window on exoplanets, planets around other suns. With its keen infrared vision, Webb will observe them in wavelengths where they have never been studied before. One of the telescope’s first observation programs is to look at young, newly formed exoplanets and the systems they inhabit. Scientists will use all four of Webb’s instruments to observe three targets: A recently discovered exoplanet; an object that is either an exoplanet or a brown dwarf; and a well-studied ring of dust and planetesimals orbiting a young star. Webb will be vital for understanding how these objects form, and what these systems are like. These observations are part of a program that allows the astronomical community to quickly learn how best to use Webb’s capabilities, while also yielding robust science.

    While we now know of thousands of exoplanets — planets around other stars — the vast majority of our knowledge is indirect. That is, scientists have not actually taken many pictures of exoplanets, and because of the limits of current technology, we can only see these worlds as points of light. However, the number of exoplanets that have been directly imaged is growing over time. When NASA’s James Webb Space Telescope launches in 2021, it will open a new window on these exoplanets, observing them in wavelengths at which they have never been seen before and gaining new insights about their nature.

    Exoplanets are close to much brighter stars, so their light is generally overwhelmed by the light of the host stars. Astronomers usually find an exoplanet by inferring its presence based on the dimming of its host star’s light as the planet passes in front of the star—an event called a “transit.” Sometimes a planet tugs on its star, causing the star to wobble slightly.

    In a few cases, scientists have captured pictures of exoplanets by using instruments called coronagraphs. These devices block the glare of the star in much the same way you might use your hand to block the light of the Sun. However, finding exoplanets with this technique has proven to be very difficult. All that will change with the sensitivity of Webb. Its onboard coronagraphs will allow scientists to view exoplanets at infrared wavelengths they’ve never seen them in before.

    Webb’s Unique Capabilities

    Coronagraphs have something important in common with eclipses. During an eclipse, the Moon blocks the light of the Sun, allowing us to view stars that would normally be overwhelmed by the Sun’s glare. Astronomers took advantage of this during the 1919 eclipse, 100 years ago on May 29, in order to test Albert Einstein’s theory of general relativity. Similarly, a coronagraph acts as an “artificial eclipse” to block the light from a star, allowing planets that would otherwise be lost in the star’s glare to be seen.

    “Most of the planets that we have detected so far are roughly 10,000 to 1 million times fainter than their host star,” explained Sasha Hinkley of the University of Exeter. Hinkley is the principal investigator on one of Webb’s first observation programs to study exoplanets and exoplanetary systems.

    “There is, no doubt, a population of planets that are fainter than that, that have higher contrast ratios, and are possibly farther out from their stars,” Hinkley said. “With Webb, we will be able to see planets that are more like 10 million, or optimistically, 100 million times fainter.” To observe their targets, the team will use high-contrast imaging, which discerns this large difference in brightness between the planet and the star.

    Webb will have the capability of observing its targets in the mid-infrared, which is invisible to the human eye, but with sensitivity that is vastly superior to any other observatory ever built. This means that Webb will be sensitive to a class of planet not yet detected. Specifically, Saturn-like planets at very wide orbital separations from their host star may be within reach of Webb.

    “Our program is looking at young, newly formed planets and the systems they inhabit,” explained co-principal investigator Beth Biller of the University of Edinburgh. “Webb is going to allow us to do this in much more detail and at wavelengths we’ve never explored before. So it’s going to be vital for understanding how these objects form, and what these systems are like.”

    Testing the Waters

    The team’s observations will be part of the Director’s Discretionary-Early Release Science program, which provides time to selected projects early in the telescope’s mission. This program allows the astronomical community to quickly learn how best to use Webb’s capabilities, while also yielding robust science.

    “With our ERS program, we will really be ‘testing the waters’ to get an understanding of how Webb performs,” said Hinkley. “We really need the best understanding of the instruments, of the stability, of the most effective way to post-process the data. Our observations are going to tell our community the most efficient way to use Webb.”

    The Targets

    Hinkley’s team will use all four of Webb’s instruments to observe three targets: A recently discovered exoplanet; an object that is either an exoplanet or a brown dwarf; and a well-studied ring of dust and planetesimals orbiting a young star.

    Exoplanet HIP 65426b: This newly discovered, directly imaged exoplanet has a mass between six and 12 times that of Jupiter and is orbiting a star that is hotter than and about twice as massive as our Sun.

    Direct imaging-This false-color composite image traces the motion of the planet Fomalhaut b, a world captured by direct imaging. Credit: NASA, ESA, and P. Kalas (University of California, Berkeley and SETI Institute

    The exoplanet is roughly 92 times farther from its star than Earth is from the Sun. The wide separation of this young planet from its star means that the team’s observations will be much less affected by the bright glare of the host star. Hinkley and his team plan to use Webb’s full suite of coronagraphs to view this target.

    Planetary-mass companion VHS 1256b: An object somewhere around the planet/brown dwarf boundary, VHS 1256b also is widely separated from its red dwarf host star—about 100 times the distance that the Earth is from the Sun. Because of its wide separation, observations of this object are much less likely to be affected by unwanted light from the host star. In addition to high-contrast imaging, the team expects to get one of the first “uncorrupted” spectra of a planet-like body at wavelengths where these objects have never before been studied.

    Circumstellar debris disk: For more than 20 years, scientists have been studying a ring of dust and planetesimals orbiting a young star called HR 4796A, which is about twice as massive as our own Sun. Astronomers think that most planetary systems probably looked a lot like HR 4796A and its debris ring at their earliest ages, making this a particularly interesting target to study. The team will use the high-contrast imaging of Webb’s coronagraphs to view the disk in different wavelengths. Their goal is to see if the structures of the disk look different from wavelength to wavelength.

    Planning the Program

    To plan this Early Release Science program, Hinkley asked as many members of the astronomical community as possible the simple question: If you want to plan a survey to search for exoplanets, what are the questions that you need the answers to for planning your surveys?

    “What we came up with was a set of observations that we think is going to answer those questions. We are going to tell the community that this is the way Webb performs in this mode, this is the kind of sensitivity we get, and this is the kind of contrast we achieve. And we need to rapidly turn that around and inform the community so that they can prepare their proposals really, really quickly.”

    The team is excited to view their targets in wavelengths never before detected, and to share their knowledge. According to Biller, “We could see years ago that for some of the planets we’ve already discovered, Webb would be really transformational.”

    The James Webb Space Telescope will be the world’s premier space science observatory when it launches in 2021. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

    See the full article here .

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    Please help promote STEM in your local schools.

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    The James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for later in the decade.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.

    NASA Webb NIRCam

    NASA Webb NIRspec

    NASA Webb MIRI

    CSA Webb Fine Guidance Sensor-Near InfraRed Imager and Slitless Spectrograph FGS/NIRISS


    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

    NASA image

    ESA50 Logo large

    Canadian Space Agency

     
  • richardmitnick 11:03 am on May 23, 2019 Permalink | Reply
    Tags: , , , , , NASA/ESA/CSA Webb   

    From Webb via Medium: “Is the James Webb Space Telescope Worth the Wait?” 

    NASA Webb Header

    NASA Webb Telescope

    James Webb Space Telescope

    via

    Medium

    May 9, 2019
    James Maynard

    Billed as the successor to Hubble, the James Webb Space Telescope (JWST) promises to bring about a new era in astronomy. This mammoth orbiting observatory is designed to answer some of the greatest and deepest questions astronomers have about the Cosmos.

    However, this project, originally conceived in 1996 for launch around 2007, has faced a series of delays and setbacks, and the telescope remains on the ground. Some members of Congress, and even the general public, are starting to ask if Webb is worth the cost and the delays. Scientists, on the other hand, are eagerly awaiting the launch with bated breath.

    2
    The golden mirror of the James Webb Space Telescope contains 18 segments, designed to captured light from the earliest ages of the Cosmos. Image credit: NASA/Desiree Stover

    “The James Webb Space Telescope will be the world’s premier space science observatory when it launches in 2021. Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it,” NASA officials explain.

    Dream Big or Stay Home

    Following an initial budget estimate of one billion dollars, costs have skyrocketed to $9.66 billion, while the launch date has slipped by more than a decade. Technical errors, equipment failures, and the government shutdown early in 2019 all combined to push back the launch of this next generation space telescope.

    For much of the time Webb was being developed, NASA was aiming for launch in October 2018. In September 2017, that date was pushed back to spring 2019. In March 2018, launch was again delayed, until May 2020. Then, in June 2018, NASA rescheduled launch for March 2021.

    One major hurdle with lifting Webb off the ground is the massive scope of the project. Engineers at NASA, faced with scientific challenges that have never before been reached, needed to develop 10 new technologies before construction could begin on the telescope. These included advanced shielding to protect the observatory from the heat of the Sun, as well as new software to keep Webb pointed at its target.

    “Among the new technologies are: near and mid-infrared detectors, sunshield materials, microshutters and wavefront sensing and control. All inventions, with the exception of wavefront sensing and control are ‘cryogenic,’ which means icy cold. It’s important for these pieces to be kept cold because the telescope will be reading heat and light from stars, and heat from instruments would get in the way of a good reading,” NASA officials explain.

    3
    The JWST will come complete with a wide range of technologies, many of which are still being developed.

    The researchers, engineers, and contractors of NASA have a can-do attitude, which can be one of their greatest strengths. It was this zeitgeist which allowed the American space agency to put astronauts on the Moon less than a decade after the project was initiated. The mindset that anything is possible also led to saving the Hubble, as well as the astronauts aboard Apollo 13. It is challenging, when an agency is faced with the prospect of developing great science like Webb proposes, to take into account the inevitable failures and setbacks which are bound to come up over time.

    “The James Webb Space Telescope is the most ambitious and complex astronomical project ever built, and bringing it to life is a long, meticulous process. The wait will be a little longer now but the breakthrough science that it will enable is absolutely worth it,” said Günther Hasinger, Director of Science at the European Space Agency (ESA), following the most recent launch delay.

    It’s Harder to Hit a Moving Target

    One challenge facing NASA is the constantly-shifting priorities of presidents and members of Congress. Unlike China, the American space program, in general, is beset by scientific targets that shift with each passing administration.

    As a prime example of this, NASA was recently directed to land human beings on the Moon once more, by the year 2024. While many people within the agency are confident of making this goal, the challenges are quite extraordinary. Meanwhile, several other countries and private organization are also planning their own human journeys to our planetary companion.


    A video showing the launch and deployment of the JWST. Credit: Northrop Grumman

    The JWST was first officially proposed to NASA in 2001, by the National Academy of Sciences, as the Next Generation Space Telescope. This massive undertaking was declared a top priority for the academy, and a one billion dollar budget was proposed for the program.

    Cost overruns are not new, or unexpected, at NASA. The Hubble Space Telescope, designed to cost $200 million, finally tallied out at $1.2 billion. Only after launch did researchers find it had reached orbit with a faulty mirror that needed correcting.

    “NASA project managers are often overly optimistic about the effort required to mature critical technologies and frequently underestimate the cost and schedule reserves needed to address known and unknown risks, optimistically assuming that most risks will not materialize. However, when they do they result in significant cost, schedule, and performance problems,” Paul Martin, NASA Inspector General, wrote in June 2018.


    A video comparing the Hubble and James Webb Space Telescopes. Credit: James Webb Space Telescope (JWST)

    Northrop Grumman, the main contractor for Webb, has been a frequent target for critics of the delays and cost overruns. Human errors have certainly contributed to problems getting Webb off the ground. One person selected an improper solvent to clean a fuel valve, while an incorrect set of wires pushed the wrong voltage into a system during a test. Just prior to another key test, the wrong fasteners were installed on the sunshield cover, resulting in another delay.

    Grumman has a large team of workers dedicated solely to building the JWST, and delays at any point in the project can result in large cost overruns. The Virginia-based contractor is constructing Webb on a cost-plus contract, meaning that cost overruns are charged to the government. Other organizations (such as SpaceX) ferrying supplies to the space station are paid on a fixed-price basis. However, Grumman officials have stated they would have been unable to make a profit on Webb if they were required to develop the telescope on a fixed-price contract.

    On Further Reflection…

    The Webb Telescope will, almost certainly, rise from Earth one day in the coming years. Assuming a successful launch, the observatory will head more than 625,000 kilometers (one million miles) from Earth, to the L2 Lagrange point, above the nighttime side of our planet. There, it will join the Planck Space Observatory and the Herschel Space Telescope.

    Sporting a mirror eight meters (25 feet) in diameter, the Webb Telescope will be capable of collecting images and data from the first stars and galaxies which came into being. This instrument will unravel some of the deepest mysteries of all about the earliest eras of the Cosmos, utilizing the largest mirror ever sent into space.

    Once Webb opens its magnificent golden eye to space, the observatory will study the oldest, most distant objects in the Cosmos in infrared light, and assist in the search for exoplanets which could be home to extraterrestrial life.

    Like so much in life, as well as science, blame for setbacks cannot be placed on the shoulders of a single person or organization. We have seen, time and again, how NASA delivers science unparalleled by any other organization in the world.

    Once the James Webb Space Telescope launches aboard an Ariane 5 rocket, the science it delivers will revolutionize our knowledge of the Universe. Hopefully, we won’t have to wait too much longer for the most-advanced telescope in the history of the world to open our view of the deepest reaches of the Cosmos.

    One thing that is certain — when the science starts pouring in, it will be worth the wait.

    [Totally ignored in this article is the contribution of money and technology for Webb by ESA and CSA. We are far beyond the point of allowable failure to launch Webb.]

    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 James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for later in the decade.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.

    NASA Webb NIRCam

    NASA Webb NIRspec

    NASA Webb MIRI

    CSA Webb Fine Guidance Sensor-Near InfraRed Imager and Slitless Spectrograph FGS/NIRISS


    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

    NASA image

    ESA50 Logo large

    Canadian Space Agency

     
  • richardmitnick 9:30 pm on October 2, 2018 Permalink | Reply
    Tags: , , , , , NASA/ESA/CSA Webb, , ,   

    From Science: “Cosmic conundrum: The disks of gas and dust that supposedly form planets don’t seem to have the goods” 

    AAAS
    From Science Magazine

    1
    Artist’s illustration of the protoplanetary disk surrounding a young star. JPL-Caltech/NASA

    Astronomers have a problem on their hands: How can you make planets if you don’t have enough of the building blocks? A new study finds that protoplanetary disks—the envelopes of dust and gas around young stars that give rise to planets—seem to contain orders of magnitude too little material to produce the planets.

    “This work is telling us that we really have to rethink our planetary formation theories,” says astronomer Gijs Mulders of the University of Chicago in Illinois, who was not involved in the research.

    Stars are born from colossal clouds of gas and dust and, in their earliest stages, are surrounded by a thin disk of material. Dust grains within this halo collide, sometimes sticking together. The clumps build up into planetary cores, which are big enough to gravitationally attract additional dust and gas, eventually forming planets.

    But many details about this process remain unknown, such as just how quickly planets arise from the disk, and how efficient they are in capturing material. The disks, surrounded by an obscuring haze of gas and dust, are difficult to observe. But radio telescopes can penetrate the haze and investigate young stars. The brightness of radio waves emitted by dust in the disk can be used to give a reasonable estimate of its overall mass.

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

    The Atacama Large Millimeter Array (ALMA), a radio observatory in the Atacama Desert in Chile, has made it far easier to study protoplanetary disks. In the new study, astronomers led by Carlo Manara of the European Southern Observatory in Munich, Germany, used ALMA to compare the masses of protoplanetary disks around young stars between 1 million and 3 million years old to the masses of confirmed exoplanets and exoplanetary systems around older stars of equivalent size. The disk masses were often much less than the total exoplanet mass—sometimes 10 or 100 times lower, the team will report in an upcoming paper in Astronomy & Astrophysics.

    Although such findings have been reported before for a few star systems, the study is the first to point out the mismatch over several hundred different systems. “I think what this work does is really set this as a fact,” Manara says.

    It is possible that astronomers are simply looking at the disks too late. Perhaps some planets form in the first million years, sucking up much of the gas and dust, Manara says. ALMA has found that some extremely young stars, such as the approximately 100,000-year-old HL Tauri, already have ringlike gaps in their disks, potentially indicating that protoplanets are sweeping up material inside of them.

    “But if you solve one problem, you end up with another,” says astronomer Jonathan Williams of the University of Hawaii Institute for Astronomy in Honolulu, who was also not involved in the work. If planetary cores form early, when so much material remains in the disk, nothing would stop them from ballooning into Jupiter-size behemoths. Yet the emerging census of exoplanets shows that most are Earth- or Neptune-size worlds.

    Williams favors the idea that current telescopes are simply missing some of the material. ALMA’s wavelengths are tuned to best see the smallest bits of dust. But a great deal of mass, perhaps as much as 10 times what’s been observed, could be hidden in the form of pebbles, which are slightly too big to show up in such investigations. A proposed upgrade to the Very Large Array, a radio telescope in New Mexico, should be able to spot such hidden debris, perhaps accounting for some of the missing material.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    One final possibility is that protoplanetary disks are somehow sucking in additional material from the surrounding interstellar medium. Manara says some recent simulations show young stars drawing in fresh material for much longer periods of time than previously believed. He hopes that observations of the earliest stages of star formation from the upcoming Square Kilometer Array or James Webb Space Telescope will help researchers decide between these different hypotheses.

    NASA/ESA/CSA Webb Telescope annotated

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 11:01 am on September 13, 2018 Permalink | Reply
    Tags: , , , BUFFALO charges towards the earliest galaxies, Caltech Buffalo, , , , , NASA/ESA/CSA Webb   

    From NASA/ESA Hubble Telescope: “BUFFALO charges towards the earliest galaxies” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    New Hubble project provides wide-field view of the galaxy cluster Abell 370.

    13 September 2018
    Charles Steinhardt
    Niels Bohr Institute
    Copenhagen, Denmark
    Tel: +45 35 33 50 10
    Email: Steinhardt@nbi.ku.dk

    Mathilde Jauzac
    Durham University
    Durham, UK
    Tel: +44 7445218614
    Email: mathilde.jauzac@durham.ac.uk

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

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

    1
    The NASA/ESA Hubble Space Telescope has started a new mission to shed light on the evolution of the earliest galaxies in the Universe. The BUFFALO survey will observe six massive galaxy clusters and their surroundings. The first observations show the galaxy cluster Abell 370 and a host of magnified, gravitationally lensed galaxies around it.

    The universe is a big place. The Hubble Space Telescope’s views burrow deep into space and time, but cover an area a fraction the angular size of the full Moon. The challenge is that these “core samples” of the sky may not fully represent the universe at large. This dilemma for cosmologists is called cosmic variance. By expanding the survey area, such uncertainties in the structure of the universe can be reduced.

    A new Hubble observing campaign, called Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO)[Caltech], will boldly expand the space telescope’s view into regions that are adjacent to huge galaxy clusters previously photographed by NASA’s Spitzer and Hubble space telescopes under a program called Frontier Fields.

    The six massive clusters were used as “natural telescopes,” to look for amplified images of galaxies and supernovas that are so distant and faint that they could not be photographed by Hubble without the boost of light caused by a phenomenon called gravitational lensing. The clusters’ large masses, mainly composed of dark matter, magnify and distort the light coming from distant background galaxies that otherwise could not be detected. The BUFFALO program is designed to identify galaxies in their earliest stages of formation, less than 800 million years after the big bang.

    2

    BUFFALO’s view on Abell 370
    The galaxy cluster Abell 370 was the first target of the BUFFALO survey, which aims to search for some of the first galaxies in the Universe.
    This remarkable cluster in the constellation of Cetus is located approximately four billion light-years away. Its mass, consisting of both hundreds of galaxies and dark matter, bends and distorts the light coming from even more distant objects behind it. This effect is known as strong gravitational lensing.
    The most stunning demonstration of gravitational lensing can be seen just below the centre of the image. Nicknamed “the Dragon”, this extended feature is made up of a multitude of duplicated images of a spiral galaxy in the background of Abell 370 — all lying five billion light-years away. Credit: NASA, ESA, A. Koekemoer, M. Jauzac, C. Steinhardt, and the BUFFALO team

    3
    The last of the Frontier Fields — Abell 370
    With the final observation of the distant galaxy cluster Abell 370 — some five billion light-years away — the Frontier Fields program came to an end.
    Abell 370 is one of the very first galaxy clusters in which astronomers observed the phenomenon of gravitational lensing, the warping of spacetime by the cluster’s gravitational field that distorts the light from galaxies lying far behind it. This manifests as arcs and streaks in the picture, which are the stretched images of background galaxies.
    Credit: NASA/ESA Hubble, HST Frontier Fields

    4
    Comparison between Frontier Fields and BUFFALO
    This image composite shows the new observations of Abell 370 made for the BUFFALO project, as well as the old observation made for the Frontier Fields programme. The composition clearly shows the extended field of view in the new observations. Credit: NASA, ESA, A. Koekemoer, M. Jauzac, C. Steinhardt, the BUFFALO team and HST Frontier Fields.

    Learning about the formation and evolution of the very first galaxies in the Universe is crucial for our understanding of the cosmos. While the NASA/ESA Hubble Space Telescope has already detected some of the most distant galaxies known, their numbers are small, making it hard for astronomers to determine if they represent the Universe at large.

    Galaxy clusters

    The immense mass of galaxy clusters like Abell 370, mainly composed of the mysterious dark matter, bends and magnifies the light of these faraway objects, turning these clusters into natural telescopes.

    This gravitational lensing effect allows scientists to see further into space beyond the cluster, by capturing the light emitted by very distant and faint objects.

    The most stunning demonstration of gravitational lensing in Abell 370 can be seen just below the centre of the cluster. Nicknamed “The Dragon” this feature is a combination of five gravitationally lensed images of the same spiral galaxy that lies beyond the cluster.

    Although Hubble has already detected some of the Universe’s earliest galaxies through its Frontier Fields programme, these fields are relatively small and might not fully represent the number of early galaxies in the wider Universe.

    BUFFALO builds upon these observations using gravitational lensing, and will expand the search area around the six Frontier Fields previously observed by Hubble. Abell 370 is the first cluster to be observed.

    Dark matter assembly

    BUFFALO will investigate how and when the most massive and luminous galaxies in the Universe formed and how they are linked to dark matter assembly – the constraining effects of which are an essential factor in how the Universe looks today. The survey will also learn more about the evolution of lensing galaxy clusters and will give clues on the nature of dark matter.

    The first step is making a detailed a dark matter mass map of these massive galaxy clusters in order to measure exactly by how much the lensed galaxies are being magnified. The programme will determine how rapidly galaxies formed in the first 800 million years after the Big Bang – paving the way for observations with the upcoming NASA/ESA/CSA James Webb Space Telescope.

    NASA/ESA/CSA Webb Telescope annotated

    Massive galaxy clusters like Abell 370, which is visible in this new image, can help astronomers find more of these distant objects. The immense masses of galaxy clusters make them act as cosmic magnifying glasses. A cluster’s mass bends and magnifies light from more distant objects behind it, uncovering objects otherwise too faint for even Hubble’s sensitive vision. Using this cosmological trick — known as strong gravitational lensing — Hubble is able to explore some of the earliest and most distant galaxies in the Universe.

    Numerous galaxies are lensed by the mass of Abell 370. The most stunning demonstration of gravitational lensing can be seen just below the centre of the cluster. Nicknamed “the Dragon”, this extended feature is made up of a multitude of duplicated images of a spiral galaxy which lies beyond the cluster.

    This image of Abell 370 and its surroundings was made as part of the new Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO) survey. This project, led by European astronomers from the Niels Bohr Institute (Denmark) and Durham University (UK), was designed to succeed the successful Frontier Fields project [1]. 101 Hubble orbits — corresponding to 160 hours of precious observation time — have been dedicated to exploring the six Frontier Field galaxy clusters. These additional observations focus on the regions surrounding the galaxy clusters, allowing for a larger field of view.

    BUFFALO’s main mission, however, is to investigate how and when the most massive and luminous galaxies in the Universe formed and how early galaxy formation is linked to dark matter assembly. This will allow astronomers to determine how rapidly galaxies formed in the first 800 million years after the Big Bang — paving the way for observations with the upcoming NASA/ESA/CSA James Webb Space Telescope.

    Driven by the Frontier Fields observations, BUFFALO will be able to detect the most distant galaxies approximately ten times more efficiently than its progenitor. The BUFFALO survey will also take advantage of other space telescopes which have already observed the regions around the clusters. These datasets will be included in the search for the first galaxies.

    The extended fields of view will also allow better 3-dimensional mapping of the mass distribution — of both ordinary and dark matter — within each galaxy cluster. These maps help astronomers learn more about the evolution of the lensing galaxy clusters and about the nature of dark matter.
    Notes

    [1] Frontier Fields was a Hubble programme that ran from 2013 to 2017. Hubble spent 630 hours of observation time probing six notable galaxy clusters, all of which showed effects of strong gravitational lensing.


    This zoom starts with a ground-based view of the sky and zooms in on the distant galaxy cluster Abell 370, as seen by the NASA/ESA Hubble Space Telescope. The mass of the cluster is large enough to bend the light of more distant objects along the line of sight. This creates interesting distortions, fascinating arcs and it even magnifies objects which would otherwise be to faint and tiny to be seen by Hubble.
    More information and download options: http://www.spacetelescope.org/videos/… Credit: ESA/Hubble Music: Richard Hasbia “Stan Dart”


    To many, Hubble is best known for its stunning images of celestial objects, but among astronomers it is admired for the valuable data it delivers. Hubble has helped revolutionise astronomy, including shedding light on dark matter and dark energy, lifting the veil on black holes, and peering into the dusty regions around stars to image exoplanets.
    This new Hubblecast is the second part of an exploration of some of Hubble’s most important discoveries throughout its history. More information and download options: http://www.spacetelescope.org/videos/… Subscribe to Hubblecast in iTunes!
    https://itunes.apple.com/gb/podcast/h…
    Receive future episodes on YouTube by pressing the Subscribe button above or follow us on Vimeo: https://vimeo.com/hubbleesa Watch more Hubblecavideo.web_category.allst episodes: http://www.spacetelescope.org/videos/… Credit: Directed by: Mathias Jäger Visual design and editing: Martin Kornmesser Written by: Lauren Fuge, Tom Barratt, Mathias Jäger Narration: Sara Mendes da Costa Images: NASA, ESA/Hubble, M. Kornmesser, HST Frontier Fields team (STScI, Risinger, Guisard, Digitized Sky Survey 2, G. Bacon (STScI) Videos: NASA, ESA/Hubble, Hubble Heritage Team, CLUES – Constrained Local Universe Evolution Simulation Animations: NASA, ESA/Hubble, M. Kornmesser, L. Calçada, G. Bacon, L. Frattare, Z. Levay, F. Summers, J. Anderson Music: Johan B. Monell (www.johanmonell.com) Web and technical support: Mathias André and Raquel Yumi Shida Executive producer: Lars Lindberg Christensen

    See the Caltech BUFFALO Project Website here.

    See the full ESA article here .
    See the full NASA article here .
    See the full Durham University article here .


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    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 4:15 pm on April 25, 2018 Permalink | Reply
    Tags: , , , , NASA/ESA/CSA Webb, NASA’s James Webb Space Telescope Could Potentially Detect the First Stars and Black Holes   

    From Webb: “NASA’s James Webb Space Telescope Could Potentially Detect the First Stars and Black Holes” 

    NASA Webb Header

    NASA Webb Telescope

    James Webb Space Telescope

    April 25, 2018

    Christine Pulliam
    Space Telescope Science Institute, Baltimore, MD, USA
    Rogier Windhorst
    Arizona State University, Tempe, AZ, USA

    Gravitational Lensing NASA/ESA

    One of the key science goals of NASA’s James Webb Space Telescope is to learn about “first light,” the moment when the first stars and galaxies lit the universe. While the first galaxies will be within Webb’s reach, individual stars shine so faintly that Webb would not be able to detect them without help. That help could come in the form of natural magnification from gravitational lensing, according to a new theoretical paper.

    NASA’s James Webb Space Telescope Could Potentially Detect the First Stars and Black Holes
    Gravitational lensing by a galaxy cluster could bring the early universe into focus for Webb

    A cluster of galaxies can provide the needed gravitational oomph to bring distant objects into focus via lensing. Typical gravitational lensing can boost a target’s brightness by a factor of 10 to 20. But in special circumstances, the light of a faraway star could be amplified by 10,000 times or more.

    If Webb monitors several galaxy clusters a couple of times a year over its lifetime, chances are good that it will detect such a magnified star, or possibly the accretion disk of a black hole from the same era. This would give astronomers a key opportunity to learn about the actual properties of the early universe and compare them to computer models.

    The first stars in the universe blazed to life about 200 to 400 million years after the big bang. Observing those very first individual stars across such vast distances of space normally would be a feat beyond any space telescope. However, new theoretical work suggests that under the right circumstances, and with a little luck, NASA’s upcoming James Webb Space Telescope will be able to capture light from single stars within that first generation of stars.

    “Looking for the first stars and black holes has long been a goal of astronomy. They will tell us about the actual properties of the very early universe, things we’ve only modeled on our computers until now,” said Rogier Windhorst of Arizona State University, Tempe. Windhorst is lead author of the paper that appeared in the Astrophysical Journal Supplement on February 14, 2018.

    “We want to answer questions about the early universe such as, were binary stars common or were most stars single? How many heavy chemical elements were produced, cooked up by the very first stars, and how did those first stars effect star formation?” added co-author Frank Timmes of Arizona State University.

    The key will be to look for a star that has been gravitationally lensed, its light bent and magnified by the gravity of an intervening galaxy cluster. But not just any gravitational lensing will do. Typical gravitational lensing can magnify light by a factor of 10 to 20 times, not enough to make a first-generation star visible to Webb.

    3
    This diagram illustrates how rays of light from a distant galaxy or star can be bent by the gravity of an intervening galaxy cluster. As a result, an observer on Earth sees the distant object appear brighter than it would look if it weren’t gravitationally lensed. CREDIT: NASA, ESA, and A. Feild and F. Summers (STScI)

    But if the distant star and closer galaxy cluster line up just right, the star’s light can be amplified 10,000 times or more, bringing it within the realm of detectability. This could be done via so-called cluster caustic transits, where the light from a first star candidate could be enormously magnified for a few months due to the motion of the galaxy cluster across the sky.

    The chances of such a precise alignment are small, but not zero. Astronomers recently announced that Hubble spotted a super-magnified star known as “Icarus.” Although it was the farthest single star ever seen, it was much closer than the stars Webb might locate. With Webb, the team hopes to find a lensed example of a star that formed from the primordial mix of hydrogen and helium that suffused the early universe, which astronomers call Population III stars.

    In addition to the first stars, Windhorst and his colleagues investigated the possibility of seeing accretion disks surrounding the first black holes. Such a black hole, formed by the cataclysmic death of a massive star, could shine brightly if it pulled gas from a companion star.

    The longer an object shines, the more likely it will drift into alignment with a gravitational lens. First-generation stars are expected to have been both massive and short-lived, lasting for just a few million years before exploding as supernovae. In contrast, a black hole stripping a companion star could shine for 10 times longer, feeding from a steady stream of gas. As a result, Webb might detect more black hole accretion disks than early stars.

    The team calculates that an observing program that targets several galaxy clusters a couple of times a year for the lifetime of Webb could succeed in finding a lensed first star or black hole accretion disk. They have already selected some of the best target clusters, including the Hubble Frontier Fields clusters and the cluster known as “El Gordo.”

    “We just have to get lucky and observe these clusters long enough,” said Windhorst. “The astronomical community would need to continue to monitor these clusters during Webb’s lifetime.”

    The authors of the Astrophysical Journal Supplement paper are R. Windhorst and F. Timmes (Arizona State University), S. Wyithe (University of Melbourne), M. Alpaslan (New York University), S. Andrews (The University of Western Australia), D. Coe (Space Telescope Science Institute), J. Diego (IFCA), M. Dijkstra (University of Oslo), S. Driver (The University of Western Australia), P. Kelly (University of Minnesota, Twin Cities), and D. Kim (Arizona State University).

    ______________________________________________________________
    The James Webb Space Telescope will be the world’s premier space science observatory. Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, the European Space Agency (ESA) and the Canadian Space Agency (CSA).
    ______________________________________________________________

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for later in the decade.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.

    NASA Webb NIRCam

    NASA Webb NIRspec

    NASA Webb MIRI

    CSA Webb Fine Guidance Sensor-Near InfraRed Imager and Slitless Spectrograph FGS/NIRISS


    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

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    Canadian Space Agency

     
  • richardmitnick 12:10 pm on January 4, 2018 Permalink | Reply
    Tags: , , , , , , CSA Webb Slitless Spectrograph (NIRISS), NASA Webb Near Infrared Imager NIRCam, NASA/ESA/CSA Webb   

    From NASA Webb: “NASA’s Webb Telescope to Investigate Mysterious Brown Dwarfs” 

    NASA Webb Header

    NASA Webb Telescope

    James Webb Space Telescope

    Jan. 4, 2018
    Leah Ramsay
    Space Telescope Science Institute, Baltimore, Md.

    Twinkle, twinkle, little star, how I wonder what you are. Astronomers are hopeful that the powerful infrared capability of NASA’s James Webb Space Telescope will resolve a puzzle as fundamental as stargazing itself — what IS that dim light in the sky? Brown dwarfs muddy a clear distinction between stars and planets, throwing established understanding of those bodies, and theories of their formation, into question.

    1
    Stellar cluster NGC 1333 is home to a large number of brown dwarfs. Astronomers will use Webb’s powerful infrared instruments to learn more about these dim cousins to the cluster’s bright newborn stars. Credits: NASA/CXC/JPL

    Several research teams will use Webb to explore the mysterious nature of brown dwarfs, looking for insight into both star formation and exoplanet atmospheres, and the hazy territory in-between where the brown dwarf itself exists. Previous work with Hubble, Spitzer, and ALMA have shown that brown dwarfs can be up to 70 times more massive than gas giants like Jupiter, yet they do not have enough mass for their cores to burn nuclear fuel and radiate starlight.

    NASA/ESA Hubble Telescope

    NASA/Spitzer Infrared Telescope

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

    Though brown dwarfs were theorized in the 1960s and confirmed in 1995, there is not an accepted explanation of how they form: like a star, by the contraction of gas, or like a planet, by the accretion of material in a protoplanetary disk? Some have a companion relationship with a star, while others drift alone in space.

    At the Université de Montréal, Étienne Artigau leads a team that will use Webb to study a specific brown dwarf, labeled SIMP0136.

    2
    SIMP0136+0933. http://www.exoplanetkyoto.org

    It is a low-mass, young, isolated brown dwarf — one of the closest to our Sun — all of which make it fascinating for study, as it has many features of a planet without being too close to the blinding light of a star. SIMP0136 was the object of a past scientific breakthrough by Artigau and his team, when they found evidence suggesting it has a cloudy atmosphere. He and his colleagues will use Webb’s spectroscopic instruments to learn more about the chemical elements and compounds in those clouds.

    “Very accurate spectroscopic measurements are challenging to obtain from the ground in the infrared due to variable absorption in our own atmosphere, hence the need for space-based infrared observation. Also, Webb allows us to probe features, such as water absorption, that are inaccessible from the ground at this level of precision,” Artigau explains.

    2
    Artist’s conception of a brown dwarf, featuring the cloudy atmosphere of a planet and the residual light of an almost-star. Credits: NASA/ESA/JPL

    These observations could lay groundwork for future exoplanet exploration with Webb, including which worlds could support life. Webb’s infrared instruments will be capable of detecting the types of molecules in the atmospheres of exoplanets by seeing which elements are absorbing light as the planet passes in front of its star, a scientific technique known as transit spectroscopy.

    “The brown dwarf SIMP0136 has the same temperature as various planets that will be observed in transit spectroscopy with Webb, and clouds are known to affect this type of measurement; our observations will help us better understand cloud decks in brown dwarfs and planet atmospheres in general,” Artigau says.

    The search for low-mass, isolated brown dwarfs was one of the early science goals put forward for the Webb telescope in the 1990s, says astronomer Aleks Scholz of the University of St. Andrews. Brown dwarfs have a lower mass than stars and do not “shine” but merely emit the dim afterglow of their birth, and so they are best seen in infrared light, which is why Webb will be such a valuable tool in this research.

    Scholz, who also leads the Substellar Objects in Nearby Young Clusters (SONYC) project, will use Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) to study NGC 1333 in the constellation of Perseus. NGC 1333 is a stellar nursery that has also been found to harbor an unusually high number of brown dwarfs, some of them at the very low end of the mass range for such objects – in other words, not much heavier than Jupiter.

    4
    NASA Webb Near Infrared Imager NIRCam

    5
    CSA Webb Slitless Spectrograph (NIRISS)

    3
    Dusty NGC 1333 is seen as a reflection nebula in visible light images, sporting bluish hues characteristic of starlight reflected by dust. But at longer infrared wavelengths, the interstellar dust itself glows – shown in red in this false-color Spitzer Space Telescope image. The penetrating infrared view also shows youthful stars that would otherwise still be obscured by the dusty clouds which formed them. Notably, greenish streaks and splotches that seem to litter the region trace the glow of cosmic jets blasting away from emerging young stellar objects as the jets plow into the cold cloud material. In all, the chaotic scene likely resembles one in which our own Sun formed over 4.5 billion years ago. NGC 1333 is a mere 1,000 light-years distant in the constellation Perseus.

    “In more than a decade of searching, our team has found it is very difficult to locate brown dwarfs that are less than five Jupiter-masses – the mass where star and planet formation overlap. That is a job for the Webb telescope,” Scholz says. “It has been a long wait for Webb, but we are very excited to get an opportunity to break new ground and potentially discover an entirely new type of planets, unbound, roaming the Galaxy like stars.”

    Both of the projects led by Scholz and Artigau are making use of Guaranteed Time Observations (GTOs), observing time on the telescope that is granted to astronomers who have worked for years to prepare Webb’s scientific operations.

    The James Webb Space Telescope, the scientific complement to NASA’s Hubble Space Telescope, will be the premier space observatory of the next decade. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

    For more information about the Webb telescope, visit http://www.nasa.gov/webb or http://www.webbtelescope.org

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for later in the decade.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.
    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

    NASA image

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    Canadian Space Agency

     
  • richardmitnick 3:14 pm on January 1, 2018 Permalink | Reply
    Tags: , , , , , NASA/ESA/CSA Webb   

    From Webb: Three articles 

    NASA Webb Header

    NASA Webb Telescope

    James Webb Space Telescope

    1. How Do We Know There Are Black Holes?


    Motion of “S2” and other stars around the central Black Hole
    An international team of astronomers, lead by researchers at the Max-Planck Institute for Extraterrestrial Physics (MPE), has directly observed an otherwise normal star orbiting the supermassive black hole at the center of the Milky Way Galaxy.

    S2 was followed closely over a period of years by Andrea Ghez, UCLA, on the UCO/Caltech Keck telescope.

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

    Black holes are among the most mysterious and fascinating features of the universe, captivating scientists since the 18th century, including Albert Einstein and Stephen Hawking. They are often described as consuming their surrounding gas, the result of gravity so intense that nothing can escape its pull, not even the fastest known traveler in the universe: light itself. But if black holes don’t emit or reflect light, which means we can’t see them, how do astronomers know they are there?

    The answer actually applies to many subjects studied in physics and deep-space astronomy—when you can’t observe something directly, or you can’t explain something you are seeing, you make educated guesses based on what you do see: the effect on other objects. On Earth, you can know it’s a windy day without stepping outside, because a flag is flapping. Astronomers know there is a black hole when the stars or gas around it are distorted or otherwise changed. These effects show up in a few ways.

    Astronomers can observe a star accelerating in orbit around an unseen companion, rather than a detectable binary companion star (see video above). By measuring the orbiting star’s rate of acceleration, astronomers can calculate the mass of the object pulling on it; when this mass is so large that nothing else can explain it, astronomers conclude it is a black hole.

    In other instances, X-ray telescopes can observe electromagnetic radiation from a star that comes close to a black hole and is pulled apart by its gravity.

    NASA/Chandra Telescope

    ESA/XMM Newton X-ray telescope

    NASA NuSTAR X-ray telescope

    These black holes accumulate cosmic matter around themselves in a swirling pattern called an accretion disk. Gas particles in the disc accelerate and collide, heating to millions of degrees and giving off the detectable X-rays.

    Black holes causing these types of phenomena are at least three times the mass of the Sun and are classified as stellar black holes.

    On a larger scale, supermassive black holes have a mass of more than one million Suns, and so must develop and grow very differently than stellar black holes. According to observations of intense gravitational attraction and energy in the center of galaxies made by the Hubble Space Telescope since the early 1990s, there is evidence for supermassive black holes at the heart of nearly all large galaxies, including our Milky Way.

    NASA/ESA Hubble Telescope

    With greater mass and thus greater gravity, supermassive black holes attract more matter that becomes hotter and more volatile. In some cases this super-heated matter shoots off into the universe as jets of gas that can be millions of light-years long. Astronomers have observed these gas ejections, known as outflow, and see it as a way of regulating galaxy expansion and the birth of new stars.

    To see the dynamic dance of dust, stars, and gas clouds being shred apart and falling into a black hole, astronomers need powerful telescopes. Hubble made significant progress in confirming and studying galactic supermassive black holes.The James Webb Space Telescope’s powerful infrared instruments will see through the cosmic dust and analyze the details of outflow, providing new information about this process and its role in galaxy evolution.

    NASA/ESA/CSA Webb Telescope annotated

    Webb mirror compared to Hubble mirror

    Webb will also be able to “see” deeper into space, and thus further back in time, to the formation of the first stars, galaxies, and perhaps black holes. Astronomers think early black holes developed at a much faster rate than black holes that are closer/more recent, which means observing these earlier cosmic citizens would shed light on the nature of their descendants, our neighbors we know well and have studied for decades.

    2. Webb and the Infancy of the Universe


    The Great Photon Escape
    In a flash known as the Big Bang, our universe was born. Yet for hundreds of thousands of years, light from the Big Bang was scattered and trapped in a dense fog. Eventually, though, that light made its “great escape” and the universe was plunged into total darkness. These cosmic “Dark Ages” lasted for millions of years until the first stars and galaxies burst to life and began to illuminate the universe. However, no one knows just when this happened, or what the earliest stars and galaxies were really like, because we’ve never seen them. The Webb telescope will use its powerful infrared vision to spy the very first stars and galaxies forming out of the darkness of the early universe and help us understand how today’s universe came to be.

    The era of the universe called the “Dark Ages” is as mysterious as its name implies.

    Shortly after the Big Bang, the universe was filled with a glowing plasma, or ionized gas. As the universe cooled and expanded, electrons and protons began to bind together to form neutral hydrogen atoms. As the last of the light from the Big Bang escaped, the universe — now about 378,000 years old — would have been a dark place, with no sources of light to illuminate its fog of cooling, neutral hydrogen gas.

    Some of that gas would have begun coalescing into dense clumps, pulled together by gravity. As these clumps grew larger and denser, they would become stars, and eventually, galaxies. Slowly, light would begin to shine again in the universe. Eventually, as the early stars grew in numbers and brightness, they would have emitted enough ultraviolet radiation to “reionize” the hydrogen, removing the electrons from their bonded protons and neutrons.

    3
    Matter in the early universe slowly accumulated into larger structures, from molecules and clouds of molecular gas to stars and eventually galaxies. Radiation from these early cosmic objects would eventually begin the time of the universe known as “reionization.” Credit: NASA/Goddard Space Flight Center and the Advanced Visualization Laboratory at the National Center for Supercomputing Applications.

    Reionization era and first stars, Caltech

    Webb, with its ability to see light from extremely distant objects that has had to travel for billions of years to reach us, will see some of the universe’s first objects. As Webb observes light that’s traveled from the far reaches of the cosmos, it captures images of distant stars and forming galaxies as they were in the earliest stages of the universe.

    Astronomers know the universe became reionized because when they look out in space and back in time at the light of very distant quasars — incredibly bright objects thought to be powered by supermassive black holes at the centers of galaxies — they don’t see the dimming of their light that would occur through a fog of neutral hydrogen gas. They find clouds of hydrogen, but almost no detectable clouds of neutral hydrogen drifting between galaxies, meaning the gas was at some point reionized. Exactly when this occurred is one of the questions Webb will help answer, by looking for glimpses of very distant objects, like quasars, still dimmed by neutral hydrogen gas.

    4
    The Hubble Ultra Deep Field is a look back in space and time that captures an estimated 10,000 galaxies in various stages of evolution, back to within 500 million years of the Big Bang. Webb’s infrared vision will allow it to reach back even farther, to see the very first stars and galaxies.

    Cosmic Conundrums

    Much remains to be uncovered about the time of reionization. The universe right after the Big Bang would have consisted of hydrogen, helium, and a small amount of lithium. But the stars we see today also contain heavier elements — elements that are created inside stars. So how did those first stars form from such limited ingredients? Webb will not be able to see the very first stars of the Dark Ages, but it’ll witness the generation immediately following, and analyze the kinds of materials they contain.

    Webb will also show us how early galaxies formed from those first clumps of stars. The universe’s first stars, believed to be 30 to 300 times as massive as our Sun and millions of times as bright, would have burned for only a few million years before dying in tremendous explosions, or “supernovae.” These explosions spewed the recently manufactured chemical elements of stars outward into the universe before the expiring stars collapsed into black holes or dim, cinder-like cores.

    Scientists suspect the black holes born from the explosion of the earliest stars devoured gas and stars around them, becoming the extremely bright objects called “mini-quasars.” The mini-quasars, in turn, may have grown and merged to become the huge black holes found in the centers of present-day galaxies. Webb will try to find and understand these supernovae and mini-quasars to put theories of early universe formation to the test.

    Webb will show us whether the first galaxies formed along filaments and webs of dark matter, as expected, and when. Right now we know the first galaxies formed anywhere from 378,000 years to 400 million years after the Big Bang. Many models have been created to explain which era gave rise to galaxies, but Webb will pinpoint the precise time period.

    3.Webb and the Universe

    5
    The collision of the Antennae galaxies triggered the formation of millions of stars in clouds of gas and dust within the galaxies. Infrared observations in this image show warm dust clouds heated by newborn stars, with the brightest clouds lying in the overlapping region between the galaxies.

    When we look out into the universe, we see galaxies with magnificent spiraling arms and galaxies that glow like giant lightbulbs. But these spiral and elliptical galaxies weren’t born in these familiar shapes. Galaxies in the early universe were probably small and clumpy. So how did these modest groups of stars evolve into the grand structures we see today?

    When telescopes peer into the universe, they look back in time. The reason is simple — light needs time to travel through space. Even the light from the Moon is 1.3 seconds old when it arrives on Earth. The most distant galaxies Hubble has spied are more than 13 billion light-years away. That means the light Hubble captures left those galaxies over 13 billion years ago.

    But there’s another complication. As the universe expands, light gets stretched into longer and longer wavelengths, turning visible light into infrared light. By the time visible light from extremely distant galaxies reaches us, it appears as infrared light. Hubble can detect some infrared light — the wavelengths closest to the red end of the visible spectrum. But infrared light will be the Webb telescope’s specialty.

    Where Hubble sees young galaxies, Webb will show us newborns. Webb will capture the earliest stages of galaxy formation, and perhaps even reveal when galaxies first started forming in the universe. Webb could show how small galaxies in the early universe merged to form larger galaxies. Finally, Webb will see more of the ordinary early galaxies, where Hubble only sees the brightest outliers. This expanded sample of early galaxies will give astronomers a better idea of how galaxies really looked as they first came into being, and help to map the universe’s overall structure.

    The Hidden Universe

    Webb’s infrared prowess will also allow it to see inside dust-cloaked regions of galaxies that visible light cannot escape from, and find out what’s happening within them. For many different types and ages of galaxies, Webb will expose how stars are forming, how many stars are forming, and how star formation is affected by the surrounding environment. Webb will study star-birth regions in merging galaxies, revealing how these galactic encounters trigger and alter the course of star formation as their gaseous components collide and mix. Webb will analyze how elements are produced and distributed in galaxies, and also examine the exchange of material between galaxies and the space between them.

    Webb will also explore an era known as the Dark Ages and the time immediately following it, the period of reionization. About 378,000 years after the Big Bang, as the universe cooled and expanded, electrons and protons began to bind together to form hydrogen atoms. As the last of the light from the Big Bang faded, the universe would have been a dark place, with no sources of light within the cooling hydrogen gas.

    6
    Light must travel through space over time. As telescopes capture light emanating from objects in the distant universe, they observe different stages of development. Webb’s infrared vision will allow it to see the first stars and galaxies to develop after the Big Bang.

    Eventually the gas would have coalesced to form stars and eventually galaxies. Over time, most of the hydrogen was “reionized,” turning it back into protons and electrons and allowing light to travel across space once again. Astronomers are currently unsure whether the energy responsible for reionization came from stars in the early forming galaxies, hot gas surrounding massive black holes, or some even more exotic source such as decaying dark matter. Webb’s infrared capabilities will allow it to identify the sources that gave rise to reionization. And perhaps Webb will see the stars and bright galaxies called “quasars” that unleashed enough energy to re-illuminate the universe.

    7
    Hubble’s eXtreme Deep Field image combines a decade of Hubble observations, including some taken in infrared light, to create one of the deepest pictures of the universe ever taken, spanning 13.2 billion years of galaxy formation. About 5,000 galaxies appear in this image.

    See the full article starting here but continuing .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for later in the decade.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.
    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

    NASA image

    ESA50 Logo large

    Canadian Space Agency

     
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