30
May 13

NASA'S Swift Reveals New Phenomenon in a Neutron Star

Source: NASA/Swift

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An artist's rendering of an outburst on an ultra-magnetic neutron star, also called a magnetar.
Image credit: NASA's Goddard Space Flight Center.

Astronomers using NASA's Swift X-ray Telescope have observed a spinning neutron star suddenly slowing down, yielding clues they can use to understand these extremely dense objects.

A neutron star is the crushed core of a massive star that ran out of fuel, collapsed under its own weight, and exploded as a supernova. A neutron star can spin as fast as 43,000 times per minute and boast a magnetic field a trillion times stronger than Earth's. Matter within a neutron star is so dense a teaspoonful would weigh about a billion tons on Earth.

This neutron star, 1E 2259+586, is located about 10,000 light-years away toward the constellation Cassiopeia. It is one of about two dozen neutron stars called magnetars, which have very powerful magnetic fields and occasionally produce high-energy explosions or pulses.

Observations of X-ray pulses from 1E 2259+586 from July 2011 through mid-April 2012 indicated the magnetar's rotation was gradually slowing from once every seven seconds, or about eight revolutions per minute. On April 28, 2012, data showed the spin rate had decreased abruptly, by 2.2 millionths of a second, and the magnetar was spinning down at a faster rate. (read more)

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29
May 13

Low Sodium Diet Key to Old Age for Stars

Source: ESO Science Release eso1323

eso1323a
The globular star cluster NGC 6752.
Image credits: ESO.

Astronomers expect that stars like the Sun will blow off much of their atmospheres into space near the ends of their lives. But new observations of a huge star cluster made using ESO’s Very Large Telescope have shown — against all expectations — that a majority of the stars studied simply did not get to this stage in their lives at all. The international team found that the amount of sodium in the stars was a very strong predictor of how they ended their lives. (read more)

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28
May 13

Ring Nebula

Source: ESA

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Hubble presents the most detailed observations ever of the Ring Nebula.
Image credits: NASA, ESA, and C. Robert O'Dell (Vanderbilt University).

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27
May 13

Giant Mysterious Blobs

Source: Space Daily

Lyman-alpha-Andromeda
Lyman-alpha blob compared with Andriomeda galaxy.
Image credit: University of Tokyo Kiso Observatory.

Blobs were first discovered about six years ago by visible-light telescopes, located billions of light-years away in ancient galactic structures or filaments, where thousands of young galaxies are clustered together. These large, fuzzy galactic halos are made up of hot hydrogen gas and are about 10 times as large as the galaxies they encompass. Astronomers can see glowing blobs, but they don't know what provides the energy to light them up. But they have a hunch.

The image above shows the immesity of a Lyman alpha blob compared to the Andromeda Galaxy in the upper right corner, scaled as if were at the same distance as the blob. The red circle indicates a bubble like structure discovered with the Subaru telescope, the 8.2 metre flagship telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii.

These huge bodies of gas may be precursors to galaxies. One of these objects, named Himiko for a legendary, mysterious Japanese queen, stretches for 55 thousand light years, a record for that early point in time. Himiko is located at a transition point in the evolution of the universe called the reionization epoch -- it's as far back as we can see to date.Extended blobs discovered thus far have mostly been seen at a distance when the universe was 2 to 3 billion years old. No extended blobs have previously been found when the universe was younger.

The image of the gigantic, amoeba-like structure is seen as it was when the universe was a mere two billion years old -- about 12 billion years ago. Normally, Lyman-alpha emission is in the ultraviolet part of the spectrum, but Lyman-apha blobs are so distant, their light is redshifted to (longer) optical wavelengths. X-ray data (blue) indicates the presence of a supermassive black hole feeding at the center of an active galaxy embedded in the blob. Lyman-alpha blobs could represent an early phase in galaxy formation where the heating is so great it begins to limit further rapid growth of active galaxies and their supermassive black holes.

Some of the gas blobs are up to 400,000 light years across, nearly twice the diameter of the Milky Way's neighboring Andromeda Galaxy. Scientists think they formed when massive stars born early in the history of the universe exploded as supernovas and blew out their surrounding gases. Another theory is that the blobs are giant gas cocoons that will one day give birth to new galaxies.

Black holes actually emit immense amounts of radiation (it's just that none of it comes from inside the event horizon). As the black hole hoovers up material, the mass spirals in towards the black hole. As it falls it's accelerated and heats up (imagine a rock falling to Earth), and hot material starts to glow. Very hot material radiates even more energy, "glowing" all the way up to X-rays.

Observations with NASA's Chandra X-ray observatory have found black holes in several blobs about eleven billion light years from Earth, at the very edge of the system's detection ability. They can't quite make out the other blobs yet, but they believe that every blob has a black hole core -- just as galaxies do -- which powers their radiation even as it eats their matter.

In fact, it's these black holes that prevents the blobs from ever becoming anything else. Such a vast cloud of matter would inevitably collapse to start creating stars unless there's something working to prop it up against gravity -- the radiation from a billion-sun-sized black hole. Which is enough to do most things.

"Something this large and this dense would have been rare in the early universe," said Ryosuke Yamauchi from Tohoku University. "The structure we discovered and others like it are probably the precursors of the largest structures we see today which contain multiple clusters of galaxies."

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26
May 13

MESSENGER Completes Its 2,000th Orbit of Mercury

Source: MESSENGER Press Release


Artist's impression  of the MESSENGER Spacecraft.
Image credits: NASA /MESSENGER.

MESSENGER Completes Its 2,000th Orbit of Mercury, Provides Data on Solar Magnetic Field

MESSENGER began its 2,000th orbit around Mercury earlier this week, on May 22. The spacecraft completed its primary mission on March 17, 2012, and its first extended mission on March 17, 2013. The team is awaiting word from NASA on a proposal for a second extended mission. In the meantime, instruments aboard the spacecraft continue to gather new data on Mercury and its environment.

From May 6 to May 14, MESSENGER traversed a superior solar conjunction, during which the spacecraft was on the far side of the Sun from Earth. Scientists used the opportunity to measure the characteristics of the solar magnetic field from the Faraday rotation of its radio-frequency carrier.

“We found the orientation of the magnetic field within a coronal mass ejection (CME) that crossed the line of sight on May 10,” says Elizabeth Jensen, of the Planetary Science Institute in Tucson, Arizona. “We saw the rotation of the plane of polarization of MESSENGER’s radio-frequency signal as it moved deeper into the corona, giving information on the Sun's magnetic field configuration on May 11; and on May 12, we saw magnetohydrodynamic waves, a very important mode of energy transfer in the corona.”

Solar storms cause communications disruptions, expose spacecraft and personnel in airplanes to radiation, and threaten electrical grids. Jensen says that the observations of the CME demonstrate the utility of this technique to predict the threat of solar storms headed toward Earth almost immediately after they erupt.

“Understanding the accuracy of models for the solar magnetic field and solar wind generation requires testing,” she says. “Although other methods can be used in active regions, Faraday rotation is the only way to test the magnetic field models in the largest part of the corona where the solar wind is accelerating.”

At its closest point to Mercury, MESSENGER will be about 447 kilometers (277.8 miles) above a point near 83.1° N latitude. Since its most recent orbit-correction maneuver on April 20, 2012, the spacecraft has completed three orbits of Mercury every day. At this rate, says mission trajectory lead James McAdams of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, the spacecraft will reach its 3,000th orbit around Mercury on April 20, 2014.

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25
May 13

Big Weather on Hot Jupiters

Source: NASA Science News

Astronomers using NASA's Spitzer Space Telescope are making weather maps of an exotic class of exoplanets called "hot Jupiters."

 

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24
May 13

Rare merger reveals secrets of galaxy evolution

Source: ESA/Herschel

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Massive galaxy merger caught in the act.
Image credits:ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO.

A rare encounter between two gas-rich galaxies spotted by ESA’s Herschel space observatory indicates a solution to an outstanding problem: how did massive, passive galaxies form in the early Universe? (read more)

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23
May 13

Most detailed observations ever of the Ring Nebula

Source:ESA/Hubble Photo Release heic1310

heic1310aThe Ring Nebula (M57).
Image credits: NASA, ESA, and C. Robert O’Dell (Vanderbilt University).

The NASA/ESA Hubble Space Telescope has produced the most detailed observations ever of the Ring Nebula (Messier 57). This image reveals intricate structure only hinted at in previous observations, and has allowed scientists to construct a model of the nebula in 3D — showing the true shape of this striking object.(read more)

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20
May 13

Proba-V opens its eyes

Source: ESA/Proba

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Proba-V’s first image.
Image credits: ESA.

Earth watcher Proba-V is in good health following its launch last week. The Vegetation imager has been switched on and the first image has been captured over western France. (read more)

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18
May 13

First new Galileo satellite arrives at ESA for space testing

Source: ESA

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The first satellite of Galileo’s next phase has arrived at ESA’s technical heart in the Netherlands for a rigorous set of tests to check its readiness for launch.(read more)

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17
May 13

NASA's Asteroid Sample Return Mission Moves into Development

Sorce: NASA News

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NASA's first mission to sample an asteroid is moving ahead into development and testing in preparation for its launch in
2016.

The Origins-Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) passed a confirmation review Wednesday called Key Decision Point (KDP)-C. NASA officials reviewed a series of detailed project assessments and authorized the spacecraft's continuation into the development phase.

OSIRIS-REx will rendezvous with the asteroid Bennu in 2018 and return a sample of it to Earth in 2023. (read more)

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15
May 13

NASA Probe Counts Space Rock Impacts on Mars

Source: NASA MRO

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Scientists using images from NASA's Mars Reconnaissance Orbiter (MRO) have estimated that the planet is bombarded by more than 200 small asteroids or bits of comets per year forming craters at least 12.8 feet (3.9 meters) across.

Researchers have identified 248 new impact sites on parts of the Martian surface in the past decade, using images from the spacecraft to determine when the craters appeared. The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet.

MRO's High Resolution Imaging Science Experiment (HiRISE) camera took pictures of the fresh craters at sites where before-and-after images by other cameras bracketed when the impacts occurred. This combination provided a new way to make direct measurements of the impact rate on Mars. This will lead to better age estimates of recent features on Mars, some of which may have been the result of climate change. (read more)

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15
May 13

Orion's Hidden Fiery Ribbon

Credit: ESO Photo Release eso1321

eso1321a

This dramatic new image of cosmic clouds in the constellation of Orion reveals what seems to be a fiery ribbon in the sky. This orange glow represents faint light coming from grains of cold interstellar dust, at wavelengths too long for human eyes to see. It was observed by the ESO-operated Atacama Pathfinder Experiment (APEX) in Chile. (read more)

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11
May 13

Planets Aligning in the Sunset Sky

Source: NASA Science Casts - YouTube

Mercury, Venus and Jupiter are lining up for a beautiful sunset conjunction at the end of May.

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9
May 13

Hubble finds dead stars "polluted" with planetary debris

Source:ESA/Hubble Science Release heic1309

heic1309a

The NASA/ESA Hubble Space Telescope has found signs of Earth-like planets in an unlikely place: the atmospheres of a pair of burnt-out stars in a nearby star cluster. The white dwarf stars are being polluted by debris from asteroid-like objects falling onto them. This discovery suggests that rocky planet assembly is common in clusters, say researchers. (read more)

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7
May 13

Herschel finds hot gas on the menu for Milky Way’s black hole

Credit: ESA/Herschel

Galactic_centre_large

ESA’s Herschel space observatory has made detailed observations of surprisingly hot molecular gas that may be orbiting or falling towards the supermassive black hole lurking at the centre of our Milky Way galaxy.(read more)

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5
May 13

Cosmic Flashes May Signal Birth of Black Holes

Source: The Daily Galaxy

BlackHole

When a massive star exhausts its fuel, it collapses under its own gravity and produces a black hole, an object so dense that not even light can escape its gravitational grip. According to a new analysis by an astrophysicist at the California Institute of Technology (Caltech), just before the black hole forms, the dying star may generate a distinct burst of light that will allow astronomers to witness the birth of a new black hole for the first time. (read more)

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3
May 13

ALMA Pinpoints Early Galaxies at Record Speed

Credit ESO Science Release 1318

eso1318a
Image credits:ALMA (ESO/NAOJ/NRAO), J. Hodge et al., A. Weiss et al., NASA Spitzer Science Center

A team of astronomers has used the new ALMA (Atacama Large Millimeter/submillimeter Array) telescope to pinpoint the locations of over 100 of the most fertile star-forming galaxies in the early Universe. ALMA is so powerful that, in just a few hours, it captured as many observations of these galaxies as have been made by all similar telescopes worldwide over a span of more than a decade.(read more)

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1
May 13

Mysterious Hurricane Spotted on Saturn

Source: NASA Science News

NASA's Cassini spacecraft has spotted a gigantic hurricane swirling inside a mysterious, six-sided weather pattern known as "the hexagon" on Saturn.(read more)

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