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  • richardmitnick 3:05 pm on June 24, 2015 Permalink | Reply
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    From Hubble: “Hubble Sees a ‘Behemoth’ Bleeding Atmosphere Around a Warm Neptune-Sized Exoplanet” 

    NASA Hubble Telescope

    Hubble

    June 24, 2015
    Felicia Chou
    NASA Headquarters, Washington, D.C.
    202-358-0257
    felicia.chou@nasa.gov

    Ann Jenkins / Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4488 / 410-338-4514
    jenkins@stsci.edu / villard@stsci.edu

    David Ehrenreich
    University of Geneva, Geneva, Switzerland
    011-41-22-379-2390
    david.ehrenreich@unige.ch

    1

    Astronomers using NASA’s Hubble Space Telescope have discovered an immense cloud of hydrogen dubbed “The Behemoth” bleeding off a planet orbiting a nearby star. The enormous, comet-like feature is about 50 times the size of the parent star. The hydrogen is evaporating from a warm, Neptune-sized planet, due to extreme radiation from the star.

    A phenomenon this large has never before been seen around any exoplanet. Given this planet’s small size, it may offer clues to how Hot Super-Earths — massive, rocky, hot versions of Earth — are born around other stars through the evaporation of their outer layers of hydrogen.

    “This cloud is very spectacular, though the evaporation rate does not threaten the planet right now,” explains the study’s leader, David Ehrenreich of the Observatory of the University of Geneva in Switzerland. “But we know that in the past, the star, which is a faint red dwarf, was more active. This means that the planet evaporated faster during its first billion years of existence. Overall, we estimate that it may have lost up to 10 percent of its atmosphere.”

    The planet, named GJ 436b, is considered to be a “Warm Neptune,” because of its size and it is much closer to its star than Neptune is to our sun. Although it is in no danger of having its atmosphere completely evaporated and being stripped down to a rocky core, this planet could explain the existence of so-called Hot Super-Earths that are very close to their stars.

    These hot, rocky worlds were discovered by the Convection Rotation and Planetary Transits (CoRoT) spacecraft (led by the French Space Agency (CNES) in collaboration with ESA (the European Space Agency), and several other international partners), and NASA’s Kepler space telescope. Hot Super-Earths could be the remnants of more massive planets that completely lost their thick, gaseous atmospheres to the same type of evaporation.

    Because Earth’s atmosphere blocks most ultraviolet light, astronomers needed a space telescope with Hubble’s ultraviolet capability and exquisite precision to find “The Behemoth.”

    “You would have to have Hubble’s eyes,” says Ehrenreich. “You would not see it in visible wavelengths. But when you turn the ultraviolet eye of Hubble onto the system, it’s really kind of a transformation, because the planet turns into a monstrous thing.”

    Because the planet’s orbit is tilted nearly edge-on to our view from Earth, the planet can be seen passing in front of its star. Astronomers also saw the star eclipsed by “The Behemoth” hydrogen cloud around the planet.

    Ehrenreich and his team think that such a huge cloud of gas can exist around this planet because the cloud is not rapidly heated and swept away by the radiation pressure from the relatively cool red dwarf star. This allows the cloud to stick around for a longer time. The team’s findings will be published in the June 25 edition of the journal Nature.

    Evaporation such as this may have happened in the earlier stages of our own solar system, when Earth had a hydrogen-rich atmosphere that dissipated over 100 million to 500 million years. If so, Earth may previously have sported a comet-like tail. It’s also possible it could happen to Earth’s atmosphere at the end of our planet’s life, when the sun swells up to become a red giant and boils off our remaining atmosphere, before engulfing our planet completely.

    GJ 436b resides very close to its star — less than 3 million miles — and whips around it in just 2.6 Earth days. (In comparison, Earth is 93 million miles from our sun and orbits it every 365.24 days.) This exoplanet is at least 6 billion years old, and may even be twice that age. It has a mass of around 23 Earths. At just 30 light-years from Earth, it’s one of the closest known extrasolar planets.

    Finding “The Behemoth” could be a game-changer for characterizing atmospheres of the whole population of Neptune-sized planets and Super-Earths in ultraviolet observations. In the coming years, Ehrenreich expects that astronomers will find thousands of this kind of planet.

    The ultraviolet technique used in this study also may spot the signature of oceans evaporating on smaller, more Earth-like planets. It will be extremely challenging for astronomers to directly see water vapor on those worlds, because it’s too low in the atmosphere and shielded from telescopes. However, when water molecules are broken by the stellar radiation into hydrogen and oxygen, the relatively light hydrogen atoms can escape the planet. If scientists could spot this hydrogen evaporating from a planet that is a bit more temperate and little less massive than GJ 436b, that is a good sign of an ocean on the surface.

    See the full article here.

    Please help promote STEM in your local schools.

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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 7:05 am on June 19, 2015 Permalink | Reply
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    From Hubble: “Quasars in interacting galaxies” 

    NASA Hubble Telescope

    Hubble

    19 June 2015

    1

    Astronomers have used the Hubble Space Telescope’s infrared vision to uncover the mysterious early formative years of quasars, the brightest objects in the universe. Hubble’s sharp images unveil chaotic galaxy collisions that give birth to quasars by fueling their energy source: a supermassive central black hole devouring infalling material.

    “The Hubble observations are definitely telling us that the peak of quasar activity in the early universe is driven by galaxies colliding and then merging together,” said Eilat Glikman of Middlebury College in Vermont. “We are seeing the quasars in their teenage years, when they are growing quickly and all messed up.”

    See the full article here.

    Please help promote STEM in your local schools.

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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 1:16 pm on June 12, 2015 Permalink | Reply
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    From NASA Hubble via Goddard: “NASA’s Hubble Telescope Detects ‘Sunscreen’ Layer on Distant Planet” 

    NASA Hubble Telescope

    Hubble

    June 11, 2015

    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

    Nancy Neal-Jones / Elizabeth Zubritsky
    Goddard Space Flight Center, Greenbelt, Md.
    301-286-0039 / 301-614-5438
    nancy.n.jones@nasa.gov / elizabeth.a.zubritsky@nasa.gov

    Last Updated: June 12, 2015
    Editor: Karen Northon


    Using NASA’s Hubble Telescope, scientists detected a stratosphere on the planet WASP-33b. A stratosphere occurs when molecules in the atmosphere absorb ultraviolet and visible light from the star. This absorption warms the stratosphere and acts as a kind of sunscreen layer for the planet below. This video is public domain and can be downloaded at: http://svs.gsfc.nasa.gov/goto? 11898
    Credits: NASA Goddard

    NASA’s Hubble Space Telescope has detected a stratosphere, one of the primary layers of Earth’s atmosphere, on a massive and blazing-hot exoplanet known as WASP-33b.

    The presence of a stratosphere can provide clues about the composition of a planet and how it formed. This atmospheric layer includes molecules that absorb ultraviolet and visible light, acting as a kind of “sunscreen” for the planet it surrounds. Until now, scientists were uncertain whether these molecules would be found in the atmospheres of large, extremely hot planets in other star systems.

    These findings will appear in the June 12 issue of the Astrophysical Journal.

    “Some of these planets are so hot in their upper atmospheres, they’re essentially boiling off into space,” said Avi Mandell, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a co-author of the study. “At these temperatures, we don’t necessarily expect to find an atmosphere that has molecules that can lead to these multilayered structures.”

    2
    WASP-33b’s stratosphere was detected by measuring the drop in light as the planet passed behind its star (top). Temperatures in the low stratosphere rise because of molecules absorbing radiation from the star (right). Without a stratosphere, temperatures would cool down at higher altitudes (left). Credits: NASA/Goddard

    In Earth’s atmosphere, the stratosphere sits above the troposphere — the turbulent, active-weather region that reaches from the ground to the altitude where nearly all clouds top out. In the troposphere, the temperature is warmer at the bottom – ground level – and cools down at higher altitudes.

    The stratosphere is just the opposite. In this layer, the temperature increases with altitude, a phenomenon called temperature inversion. On Earth, temperature inversion occurs because ozone in the stratosphere absorbs much of the sun’s ultraviolet radiation, preventing it from reaching the surface, protecting the biosphere, and therefore warming the stratosphere instead.

    Similar temperature inversions occur in the stratospheres of other planets in our solar system, such as Jupiter and Saturn. In these cases, the culprit is a different group of molecules called hydrocarbons. Neither ozone nor hydrocarbons, however, could survive at the high temperatures of most known exoplanets, which are planets outside our solar system. This leads to a debate as to whether stratospheres would exist on them at all.

    Using Hubble, the researchers have settled this debate by identifying a temperature inversion in the atmosphere of WASP-33b, which has about four-and-a-half times the mass of Jupiter. Team members also think they know which molecule in WASP-33b’s atmosphere caused the inversion — titanium oxide.

    “These two lines of evidence together make a very convincing case that we have detected a stratosphere on an exoplanet,” said Korey Haynes, lead author of the study. Haynes was a graduate student at George Mason University in Fairfax, Virginia, and was working at Goddard with Mandell when the research was conducted.

    The researchers analyzed observations made with Hubble’s Wide Field Camera 3 by co-author Drake Deming at the University of Maryland in College Park. Wide Field Camera 3 can capture a spectrum of the near-infrared region where the signature for water appears. Scientists can use the spectrum to identify water and other gases in a distant planet’s atmosphere and determine its temperature.

    Haynes and her colleagues used the Hubble observations, and data from previous studies, to measure emission from water and compare it to emission from gas deeper in the atmosphere. The team determined that emission from water was produced in the stratosphere at about 6,000 degrees Fahrenheit. The rest of the emission came from gas lower in the atmosphere that was at a temperature about 3,000 degrees Fahrenheit.

    The team also presented the first observational evidence that WASP-33b’s atmosphere contains titanium oxide, one of only a few compounds that is a strong absorber of visible and ultraviolet radiation and capable of remaining in gaseous form in an atmosphere as hot as this one.

    “Understanding the links between stratospheres and chemical compositions is critical to studying atmospheric processes in exoplanets,” said co-author Nikku Madhusudhan of the University of Cambridge, United Kingdom. “Our finding marks a key breakthrough in this direction.”

    For images and more information about Hubble, visit:

    http://www.nasa.gov/hubble

    See the full article here.

    Please help promote STEM in your local schools.

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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 7:55 am on June 6, 2015 Permalink | Reply
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    From Hubble: “Hubblecast episode 85: Ode to Hubble” 

    NASA Hubble Telescope

    Hubble

    To celebrate Hubble’s 25th birthday ESA/Hubble asked the public to produce and submit short videos illustrating how Hubble has inspired them. This new Hubblecast episode presents the two winning videos. The episode also introduces us to the creators of the videos and they explain how they produced the videos and the inspiration for creating them.

    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 Hubblecast episodes: http://www.spacetelescope.org/videos/…

    Find out how to view and contribute subtitles for the Hubblecast in multiple languages, or translate this video on dotSUB: http://www.eso.org/public/outreach/pa…


    Watch, enjoy, learn.

    See the full article here.

    Please help promote STEM in your local schools.

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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 1:43 pm on June 3, 2015 Permalink | Reply
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    From Hubble: “Hubble Finds Two Chaotically Tumbling Pluto Moons” 

    NASA Hubble Telescope

    Hubble

    1
    Pluto and its satellites

    Object Name: Nix, Hydra, Styx, Kerberos
    Object Description: Minor Moons of the Pluto-Charon System
    Properties:
    Discovery Year Semi-major axis (in km) Period (in days)
    Styx 2012 42,700 20.2
    Nix 2005 48,700 24.9
    Kerberos 2011 57,800 32.2
    Hydra 2005 64,800 38.2

    June 3, 2015
    CONTACT

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

    Felicia Chou
    NASA Headquarters, Washington, D.C.
    202-358-0257
    felicia.chou@nasa.gov

    Mark Showalter
    SETI Institute, Mountain View, California
    605-810-0234
    mshowalter@seti.org

    Doug Hamilton
    University of Maryland, College Park, Maryland
    301-405-1548
    dhamil@astro.umd.edu

    If you lived on one of Pluto’s moons Nix or Hydra, you’d have a hard time setting your alarm clock. That’s because you could not know for sure when, or even in which direction, the sun would rise.

    2
    Pluto photographed by the New Horizons spacecraft in May 2015

    A comprehensive analysis of all available Hubble Space Telescope data shows that two of Pluto’s moons, Nix and Hydra, are wobbling unpredictably. Scientists believe the other two small moons, Kerberos and Styx, are likely in a similar situation, pending further study.

    “Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington, D.C. “When the New Horizons spacecraft flies through the Pluto system in July we’ll get a chance to see what these moons look like up close and personal.”

    NASA New Horizons spacecraft II
    New Horizons

    Why the chaos? Because the moons are embedded inside a dynamically shifting gravitational field caused by the system’s two central bodies, Pluto and Charon, whirling about each other. The variable gravitational field induces torques that send the smaller moons tumbling in unpredictable ways. This torque is strengthened by the fact the moons are football shaped rather than spherical.

    The surprising results of the Hubble research, conducted by Mark Showalter of the SETI Institute in Mountain View, California, and Doug Hamilton of the University of Maryland at College Park, are appearing in the June 4 issue of the British science journal Nature.

    “Prior to the Hubble observations nobody appreciated the intricate dynamics of the Pluto system,” Showalter said. “Our report provides important new constraints on the sequence of events that led to the formation of the system.”

    4
    Image of the Plutonian system

    Hubble’s monitoring of Pluto’s four outer moons has also revealed that three of them, Nix, Styx, and Hydra, are presently locked together in resonance where there is a precise ratio among their orbital periods. “This ties together their motion in a way similar to that of three of Jupiter’s large moons,” noted Hamilton. “If you were sitting on Nix you would see that Styx orbits Pluto twice for every three orbits made by Hydra.”

    Hubble provides observational evidence that the satellites are also orbiting chaotically. “However, that does not necessarily mean that the system is on the brink of flying apart,” Showalter added. “We need to know a lot more about the system before we can determine its long-term fate.”

    To the surprise of astronomers, Hubble also found that the moon Kerberos is as dark as a charcoal briquette, while the other satellites are as bright as white sand. It was predicted that pollution by dust blasted off the satellites by meteorite impacts should overcoat all the moons, giving their surfaces a homogeneous look. “This is a very provocative result,” Showalter said.

    NASA’s New Horizons probe, which will fly by the Pluto-Charon system in July 2015, may help settle the question of the asphalt-black moon as well as the other oddities uncovered by Hubble. These new discoveries are being used in the science planning for New Horizons’s observations.

    The chaos in the Pluto-Charon system offers insights into how planets orbiting a double-star might behave. “We are learning that chaos may be a common trait of binary systems,” Hamilton said. “It might even have consequences for life on planets in such systems.” NASA’s Kepler space observatory has found several planetary systems orbiting double stars.

    NASA Kepler Telescope
    Kepler

    Clues to the Pluto chaos first came when astronomers measured variations in the light reflected off of the two moons Nix and Hydra. Their brightness changed unpredictably. “The data were confusing; they made no sense at all. We had an inkling something was fishy,” Showalter said. His team analyzed Hubble images of Pluto taken during 2005-2012. They compared the unpredictable changes in the moons’ reflectivity to dynamical models of spinning bodies in complex gravitational fields.

    Virtually all large moons, as well as small moons in close-in orbits, keep one hemisphere facing their parent planet. This means that the satellite’s rotation is perfectly matched to the orbital period. This is not coincidental, but the consequence of gravitational tides between moon and planet. (Hyperion, which orbits Saturn, is the only other solar-system example of chaotic rotation; it is due to the combined gravitational tugs of the planet and it largest moon, Titan).

    Pluto’s moons are hypothesized to have formed by a collision between the dwarf planet and another similar-sized body early in the history of the solar system. The smashup flung material that coalesced into the family of satellites observed around Pluto today. Its large binary companion, Charon, was discovered in 1978. The object is almost half the size of Pluto. Hubble discovered Nix and Hydra in 2005, Kerberos in 2011, and Styx in 2012. These little moons, measuring just tens of miles across, were found as part of a Hubble search for potential hazards to the New Horizons spacecraft flyby.

    Pluto and Charon are called a double planet because they orbit about a common center of gravity that is located in the space between the bodies. Some regard the Earth-moon system as a double planet, too, although the center of gravity falls beneath Earth’s surface. (Our moon has 1/80th of Earth’s mass, whereas Charon has 1/8th of Pluto’s mass.)

    Researchers say that a combination of monitoring data from Hubble, New Horizons’s brief close-up look, and eventually, observations with the James Webb Space Telescope will help settle many mysteries of the Pluto-Charon system. No ground-based telescopes have yet been able to detect the smallest moons.

    NASA Webb Telescope
    Webb

    “Pluto will continue to surprise us when New Horizons flies past it in July,” Showalter said. “Our work with the Hubble telescope just gives us a foretaste of what’s in store.”

    See the full article here.

    Please help promote STEM in your local schools.

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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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    • Matthew Wright 6:41 pm on June 3, 2015 Permalink | Reply

      Awesome stuff. It’s amazong what can be calculated from partial data. I figure this is a taster for the flood of info we’ll get about the Pluto system in a few months. And then will come the years of analysis which may well reveal other left-field discoveries about Pluto.

      Like

  • richardmitnick 11:43 am on June 2, 2015 Permalink | Reply
    Tags: , , NASA/ESA Hubble,   

    From Hubble: “Merging galaxies break radio silence” 

    NASA Hubble Telescope

    Hubble

    28 May 2015
    Contacts
    Marco Chiaberge
    Space Telescope Science Institute, USA
    Johns Hopkins University, USA, INAF-IRA, Italy
    Tel: +1 410 338 4980
    Email: marcoc@stsci.edu

    Roberto Gilli
    INAF
    Osservatorio Astronomico di Bologna, Italy
    Tel: +39 051 2095 719
    Cell: +39 347 4139847
    Email: roberto.gilli@oabo.inaf.it

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

    1

    In the most extensive survey of its kind ever conducted, a team of scientists have found an unambiguous link between the presence of supermassive black holes that power high-speed, radio-signal-emitting jets and the merger history of their host galaxies. Almost all of the galaxies hosting these jets were found to be merging with another galaxy, or to have done so recently. The results lend significant weight to the case for jets being the result of merging black holes and will be presented in the Astrophysical Journal.

    A team of astronomers using the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 (WFC3) have conducted a large survey to investigate the relationship between galaxies that have undergone mergers and the activity of the supermassive black holes at their cores.

    NASA Hubble WFC3
    WFC3

    The team studied a large selection of galaxies with extremely luminous centres — known as active galactic nuclei (AGNs) — thought to be the result of large quantities of heated matter circling around and being consumed by a supermassive black hole. Whilst most galaxies are thought to host a supermassive black hole, only a small percentage of them are this luminous and fewer still go one step further and form what are known as relativistic jets [1]. The two high-speed jets of plasma move almost with the speed of light and stream out in opposite directions at right angles to the disc of matter surrounding the black hole, extending thousands of light-years into space. The hot material within the jets is also the origin of radio waves.

    It is these jets that Marco Chiaberge from the Space Telescope Science Institute, USA (also affiliated with Johns Hopkins University, USA and INAF-IRA, Italy) and his team hoped to confirm were the result of galactic mergers [2].

    The team inspected five categories of galaxies for visible signs of recent or ongoing mergers — two types of galaxies with jets, two types of galaxies that had luminous cores but no jets, and a set of regular inactive galaxies [3].

    “The galaxies that host these relativistic jets give out large amounts of radiation at radio wavelengths,” explains Marco. “By using Hubble’s WFC3 camera we found that almost all of the galaxies with large amounts of radio emission, implying the presence of jets, were associated with mergers. However, it was not only the galaxies containing jets that showed evidence of mergers!” [4].

    “We found that most merger events in themselves do not actually result in the creation of AGNs with powerful radio emission,” added co-author Roberto Gilli from Osservatorio Astronomico di Bologna, Italy. “About 40% of the other galaxies we looked at had also experienced a merger and yet had failed to produce the spectacular radio emissions and jets of their counterparts.”

    Although it is now clear that a galactic merger is almost certainly necessary for a galaxy to host a supermassive black hole with relativistic jets, the team deduce that there must be additional conditions which need to be met. They speculate that the collision of one galaxy with another produces a supermassive black hole with jets when the central black hole is spinning faster — possibly as a result of meeting another black hole of a similar mass — as the excess energy extracted from the black hole’s rotation would power the jets.

    “There are two ways in which mergers are likely to affect the central black hole. The first would be an increase in the amount of gas being driven towards the galaxy’s centre, adding mass to both the black hole and the disc of matter around it,” explains Colin Norman, co-author of the paper. “But this process should affect black holes in all merging galaxies, and yet not all merging galaxies with black holes end up with jets, so it is not enough to explain how these jets come about. The other possibility is that a merger between two massive galaxies causes two black holes of a similar mass to also merge. It could be that a particular breed of merger between two black holes produces a single spinning supermassive black hole, accounting for the production of jets.”

    Future observations using both Hubble and the Atacama Large Millimeter/submillimeter Array (ALMA) are needed to expand the survey set even further and continue to shed light on these complex and powerful processes.

    ALMA Array
    ALMA

    Notes

    [1] Relativistic jets travel at close to the speed of light, making them one of the fastest astronomical objects known.

    [2] The new observations used in this research were taken in collaboration with the 3CR-HST team. This international team of astronomers is currently led by Marco Chiaberge and has conducted a series of surveys of radio galaxies and quasars from the 3CR catalogue using the Hubble Space Telescope.

    [3] The team compared their observations with the swathes of archival data from Hubble. They directly surveyed twelve very distant radio galaxies and compared the results with data from a large number of galaxies observed during other observing programmes.

    [4] Other studies had shown a strong relationship between the merger history of a galaxy and the high levels of radiation at radio wavelengths that suggests the presence of relativistic jets lurking at the galaxy’s centre. However, this survey is much more extensive, and the results very clear, meaning it can now be said with almost certainty that radio-loud AGNs, that is, galaxies with relativistic jets, are the result of galactic mergers.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

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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 1:38 pm on May 27, 2015 Permalink | Reply
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    From Hubble: “Hubble Video Shows Shock Collision Inside Black Hole Jet” 

    NASA Hubble Telescope

    Hubble

    May 27, 2015
    CONTACT

    Felicia Chou
    NASA Headquarters, Washington, D.C.
    202-358-0257
    felicia.chou@nasa.gov

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

    1
    Object Name: 3C 264
    Object Description: Active Radio Galaxy
    Constellation: Leo
    Distance: 300 million light-years (91 Mpc)

    The science team comprises: E. Meyer (STScI), M. Georganopoulos (UMBC/NASA GSFC), W.B. Sparks (STScI), E. Perlman (Florida Institute of Technology), R. van der Marel, J. Anderson (STScI), S.T. Sohn (JHU), J. Biretta (STScI), C. Norman (STScI/JHU), and M. Chiaberge (STScI/ESA).

    When you’re blasting though space at more than 98 percent of the speed of light, you may need driver’s insurance. Astronomers have discovered for the first time a rear-end collision between two high-speed knots of ejected matter from a super-massive black hole. This discovery was made while piecing together a time-lapse movie of a plasma jet blasted from a supermassive black hole inside a galaxy located 260 million light-years from Earth. [The “movie is presented on the original article. I could not make it work in this post.]

    The finding offers new insights into the behavior of “light-saber-like” jets that are so energized that they appear to zoom out of black holes at speeds several times the speed of light. This “superluminal” motion is an optical illusion due to the very fast real speed of the plasma, which is close to the universal maximum of the speed of light.

    Such extragalactic jets are not well understood. They appear to transport energetic plasma in a confined beam from the central black hole of the host galaxy. The new analysis suggests that shocks produced by collisions within the jet further accelerate particles and brighten the regions of colliding material.

    The video of the jet was assembled with two decades’ worth of NASA Hubble Space Telescope images of the elliptical galaxy NGC 3862, the sixth brightest galaxy and one of only a few active galaxies with jets seen in visible light. The jet was discovered in optical light by Hubble in 1992. NGC 3862 is in a rich cluster of galaxies known as Abell 1367.

    5
    NGC 3862 best image available

    3
    Abell 1367

    The jet from NGC 3862 has a string-of-pearls structure of glowing knots of material. Taking advantage of Hubble’s sharp resolution and long-term optical stability, Eileen Meyer of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, matched archival Hubble images with a new, deep image taken in 2014 to better understand jet motions. Meyer was surprised to see a fast knot with an apparent speed of seven times the speed of light catch up with the end of a slower moving, but still superluminal, knot along the string.

    The resulting “shock collision” caused the merging blobs to brighten significantly.

    “Something like this has never been seen before in an extragalactic jet,” said Meyer. As the knots continue merging they will brighten further in the coming decades. “This will allow us a very rare opportunity to see how the kinetic energy of the collision is dissipated into radiation.”

    It’s not uncommon to see knots of material in jets ejected from gravitationally compact objects, but it is rare that motions have been observed with optical telescopes, and so far out from the black hole, thousands of light-years away. In addition to black holes, newly forming stars eject narrowly collimated streamers of gas that have a knotty structure. One theory is that material falling onto the central object is superheated and ejected along the object’s spin axis. Powerful magnetic fields constrain the material into a narrow jet. If the flow of the infalling material is not smooth, blobs are ejected like a string of cannon balls rather than a steady hose-like flow.

    Whatever the mechanism, the fast-moving knot will burrow its way out into intergalactic space. A knot launched later, behind the first one, may have less drag from the shoveled-out interstellar medium and catch up to the earlier knot, rear-ending it in a shock collision.

    Beyond the collision, which will play out over the next few decades, this discovery marks only the second case of superluminal motion measured at hundreds to thousands of light-years from the black hole where the jet was launched. This indicates that the jets are still very, very close to the speed of light even on distances that start to rival the scale of the host galaxy. These measurements can give insights into how much energy jets carry out into their host galaxy and beyond, which is important for understanding how galaxies evolve as the universe ages.

    Meyer is currently making a Hubble-image video of two more jets in the nearby universe, to look for similar fast motions. She notes that these kinds of studies are only possible because of the long operating lifetime of Hubble, which has now been looking at some of these jets for over 20 years.

    Extragalactic jets have been detected at X-ray and radio wavelengths in many active galaxies powered by central black holes, but only a few have been seen in optical light. Astronomers do not yet understand why some jets are seen in visible light and others are not.

    Meyer’s results are being reported in the May 28 issue of the journal Nature.

    See the full article here.

    Please help promote STEM in your local schools.

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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 1:21 pm on May 22, 2015 Permalink | Reply
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    From Hubble: “Hubble’s Look at an Extragalactic Peculiarity” 

    NASA Hubble Telescope

    Hubble

    May 22, 2015
    Karl Hille

    1
    NASA/ESA Hubble

    This galaxy goes by the name of ESO 162-17 and is located about 40 million light-years away in the constellation of Carina. At first glance this image seems like a fairly standard picture of a galaxy with dark patches of dust and bright patches of young, blue stars. However, a closer look reveals several peculiar features.

    Firstly, ESO 162-17 is what is known as a peculiar galaxy — a galaxy that has gone through interactions with its cosmic neighbors, resulting in an unusual amount of dust and gas, an irregular shape, or a strange composition.

    Secondly, on February 23, 2010 astronomers observed the supernova known as SN 2010ae nestled within this galaxy. The supernova belongs to a recently discovered class of supernovae called Type Iax supernovae. This class of objects is related to the better known Type-Ia supernovae.

    Type Ia supernovae result when a white dwarf accumulates enough mass either from a companion or, rarely, through collision with another white dwarf, to initiate a catastrophic collapse followed by a spectacular explosion as a supernova. Type Iax supernovae also involve a white dwarf as the central star, but in this case it may survive the event. Type Iax supernovae are much fainter and rarer than Type Ia supernovae, and their exact mechanism is still a matter of open debate.

    The rather beautiful four-pointed shape of foreground stars distributed around ESO 162-17 also draws the eye. This is an optical effect introduced as the incoming light is diffracted by the four struts that support the Hubble Space Telescope’s small secondary mirror.

    See the full article here.

    Please help promote STEM in your local schools.

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    Stem Education Coalition

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

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  • richardmitnick 1:05 pm on May 22, 2015 Permalink | Reply
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    From Hubble: “Hubble Revisits Tangled NGC 6240″ 

    NASA Hubble Telescope

    Hubble

    May 22, 2015
    Ashley Morrow

    1
    Image credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

    Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown here in a pinky-red hue at the center of the galaxies, was only revealed in these new observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys.

    NASA Hubble WFC3
    WFC3

    NASA Hubble ACS
    ACS

    NGC 6240 lies 400 million light-years away in the constellation of Ophiuchus (The Serpent Holder). This galaxy has an elongated shape with branching wisps, loops and tails. This mess of gas, dust and stars bears more than a passing resemblance to a butterfly and a lobster.

    This bizarrely-shaped galaxy did not begin its life looking like this; its distorted appearance is a result of a galactic merger that occurred when two galaxies drifted too close to one another. This merger sparked bursts of new star formation and triggered many hot young stars to explode as supernovae. A new supernova, not visible in this image was discovered in this galaxy in 2013, named SN 2013dc.

    At the center of NGC 6240 an even more interesting phenomenon is taking place. When the two galaxies came together, their central black holes did so, too. There are two supermassive black holes within this jumble, spiraling closer and closer to one another. They are currently only some 3,000 light-years apart, incredibly close given that the galaxy itself spans 300,000 light-years. This proximity secures their fate as they are now too close to escape each other and will soon form a single immense black hole.

    See the full article here.

    Please help promote STEM in your local schools.

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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 5:00 pm on May 21, 2015 Permalink | Reply
    Tags: , , NASA/ESA Hubble   

    From Hubble: “Hubble Observes One-of-a-Kind Star Nicknamed ‘Nasty'” 

    NASA Hubble Telescope

    Hubble

    May 21, 2015
    Donna Weaver / Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493 / 410-338-4514
    dweaver@stsci.edu / villard@stsci.edu

    1
    Object Name: NaSt1, Wolf-Rayet 122, WR 122
    Object Description: Emission-line Star with Nebula
    Instrument: WFC3/UVIS
    Exposure Date(s): April 27, 2013
    Credit: NASA, ESA, and J. Mauerhan (University of California, Berkeley)
    Release Date: May 21, 2015

    Astronomers using NASA’s Hubble Space Telescope have uncovered surprising new clues about a hefty, rapidly aging star whose behavior has never been seen before in our Milky Way galaxy. In fact, the star is so weird that astronomers have nicknamed it “Nasty 1,” a play on its catalog name of NaSt1. The star may represent a brief transitory stage in the evolution of extremely massive stars.

    First discovered several decades ago, Nasty 1 was identified as a Wolf-Rayet star, a rapidly evolving star that is much more massive than our sun. The star loses its hydrogen-filled outer layers quickly, exposing its super-hot and extremely bright helium-burning core.

    But Nasty 1 doesn’t look like a typical Wolf-Rayet star. The astronomers using Hubble had expected to see twin lobes of gas flowing from opposite sides of the star, perhaps similar to those emanating from the massive star Eta Carinae, which is a Wolf-Rayet candidate.

    2
    A huge, billowing pair of gas and dust clouds are captured in this stunning NASA Hubble Space Telescope image of the supermassive star Eta Carinae.

    Instead, Hubble revealed a pancake-shaped disk of gas encircling the star. The vast disk is nearly 2 trillion miles wide, and may have formed from an unseen companion star that snacked on the outer envelope of the newly formed Wolf-Rayet. Based on current estimates, the nebula surrounding the stars is just a few thousand years old, and as close as 3,000 light-years from Earth.

    “We were excited to see this disk-like structure because it may be evidence for a Wolf-Rayet star forming from a binary interaction,” said study leader Jon Mauerhan of the University of California, Berkeley. “There are very few examples in the galaxy of this process in action because this phase is short-lived, perhaps lasting only a hundred thousand years, while the timescale over which a resulting disk is visible could be only ten thousand years or less.”

    According to the team’s scenario, a massive star evolves very quickly, and as it begins to run out of hydrogen, it swells up. Its outer hydrogen envelope becomes more loosely bound and vulnerable to gravitational stripping, or a type of stellar cannibalism, by the nearby companion star. In that process, the more compact star winds up gaining mass, and the original massive star loses its hydrogen envelope, exposing its helium core to become a Wolf-Rayet star.

    Another way Wolf-Rayet stars are said to form is when a massive star ejects its own hydrogen envelope in a strong stellar wind streaming with charged particles. The binary interaction model where a companion star is present is gaining traction because astronomers realize that at least 70 percent of massive stars are members of double-star systems. Direct mass loss alone also cannot account for the number of Wolf-Rayet stars relative to other less-evolved massive stars in the galaxy.

    “We’re finding that it is hard to form all the Wolf-Rayet stars we observe by the traditional wind mechanism, because mass loss isn’t as strong as we used to think,” said Nathan Smith of the University of Arizona in Tucson, who is a co-author on the new NaSt1 paper. “Mass exchange in binary systems seems to be vital to account for Wolf-Rayet stars and the supernovae they make, and catching binary stars in this short-lived phase will help us understand this process.”

    But the mass-transfer process in mammoth binary systems isn’t always efficient. Some of the stripped matter can spill out during the dynamical gravitational tussle between the stars, creating a disk around the binary.

    “That’s what we think is happening in Nasty 1,” Mauerhan said. “We think there is a Wolf-Rayet star buried inside the nebula, and we think the nebula is being created by this mass-transfer process. So this type of sloppy stellar cannibalism actually makes Nasty 1 a rather fitting nickname.”

    The star’s catalog name, NaSt1, is derived from the first two letters of each of the two astronomers who discovered it in 1963, Jason Nassau and Charles Stephenson.

    Viewing the Nasty 1 system hasn’t been easy. The system is so heavily cloaked in gas and dust, it blocks even Hubble’s view of the stars. So Mauerhan’s team cannot measure the mass of each star, the distance between them, or the amount of material spilling onto the companion star.

    Previous observations of Nasty 1 have provided some information on the gas in the disk. The material, for example, is travelling about 22,000 miles per hour in the outer nebula, slower than similar stars. The comparatively slow speed indicates that the star expelled its material through a less violent event than Eta Carinae’s explosive outbursts, where the gas is travelling hundreds of thousands of miles per hour.

    Nasty 1 may also be shedding the material sporadically. Past studies in infrared light have shown evidence for a compact pocket of hot dust very close to the central stars. Recent observations by Mauerhan and colleagues at the University of Arizona, using the Magellan telescope at Las Campanas Observatory in Chile, have resolved a larger pocket of cooler dust that may be indirectly scattering the light from the central stars.

    Magellan 6.5 meter telescopes
    Magellan 6.5 meter Interior
    Magellan Telescope

    The presence of warm dust implies that it formed very recently, perhaps in spurts, as chemically enriched material from the two stellar winds collides at different points, mixes, flows away, and cools. Sporadic changes in the wind strength or the rate the companion star strips the main star’s hydrogen envelope might also explain the clumpy structure and gaps seen farther out in the disk.

    To measure the hypersonic winds from each star, the astronomers turned to NASA’s Chandra X-ray Observatory.

    NASA Chandra Telescope
    Chandra

    The observations revealed scorching hot plasma, indicating that the winds from both stars are indeed colliding, creating high-energy shocks that glow in X-rays. These results are consistent with what astronomers have observed from other Wolf-Rayet systems.

    The chaotic mass-transfer activity will end when the Wolf-Rayet star runs out of material. Eventually, the gas in the disk will dissipate, providing a clear view of the binary system.

    “What evolutionary path the star will take is uncertain, but it will definitely not be boring,” said Mauerhan. “Nasty 1 could evolve into another Eta Carinae-type system. To make that transformation, the mass-gaining companion star could experience a giant eruption because of some instability related to the acquiring of matter from the newly formed Wolf-Rayet. Or, the Wolf-Rayet could explode as a supernova. A stellar merger is another potential outcome, depending on the orbital evolution of the system. The future could be full of all kinds of exotic possibilities depending on whether it blows up or how long the mass transfer occurs, and how long it lives after the mass transfer ceases.”

    The team’s results will appear May 21 in the online edition of the Monthly Notices of the Royal Astronomical Society.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

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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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