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In the violent heart of our Milky Way galaxy lies a supermassive black hole with a mass equivalent to four million suns. But although the gravitational maw gobbles up anything that gets too close, it can also set up conditions that allow for the birth of new stars just a few light years away, according to a new study. Lead researcher Elizabeth Humphreys says the results, which uncovered what appear to be two young stars as close as seven light-years from the galactic center, were surprising, as that is “one of the last places … you would expect to find stars forming” [Scientific American].

Gas clouds that approach a black hole are usually ripped apart by the intense gravitational forces, but the new finding suggests that the molecular gas at the center of the Milky Way from which the stars form is denser than previously thought. The higher density gas makes it easier for the self-gravity of the condensing cloud to overcome the strong pull of the black hole and to collapse to form new stars [SPACE.com].

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Dead stars surrounded by fields of dust from pulverized asteroids may seem to make up a forbidding and ominous picture, but researchers who studied six such star systems say the dust should actually fuel the optimism of people who dream of finding extraterrestrial life. The dust’s composition suggests that rocky planets like our own Earth may be common in the universe, researchers say, which ups the chance that life as we know it has evolved somewhere out there.

The dust in question was found surrounding small, dense white dwarf stars. As stars like our own sun near the end of their life, they puff up into red giants that consume their innermost planets and jostle the orbits of outer planets and asteroids. Eventually the stars blow off their outer layers and shrink down into white dwarfs. Occasionally, a perturbed asteroid will wander too close to the white dwarf, whose gravity rips the rocky body to shreds, forming debris [SPACE.com].

That debris is what researchers studied with NASA’s Spitzer Space Telescope. By viewing the stars through a spectrograph, which separates out light from different wavelengths, the scientists were able to observe the telltale signatures of certain chemicals in the light. Since that starlight is passing through the film of the asteroid debris, the light picked up signatures of the asteroids’ composition, too [Wired News]. Lead researcher Michael Jura announced at the ongoing American Astronomical Society meeting that the composition of the asteroid dust was remarkably similar to that of the rocky planets in our solar system.

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We residents of the Milky Way can puff ourselves up with pride: A new study has discovered that our galaxy is more of a force to be reckoned with than previously realized. Astronomers said Monday that the Milky Way is more massive than earlier known, given new measurements showing that the Sun is moving at 600,000 miles per hour around the center of the galaxy, or 100,000 m.p.h. faster than past calculations suggested. The higher speed of the Sun means the galaxy must have more mass — about 50 percent more — so as to generate a stronger gravitational pull to keep hold of the Sun, as well as all its other stars [The New York Times].

The new calculation puts our galaxy’s mass about equal to that of the nearby Andromeda galaxy, which was previously thought to be bigger than the Milky Way, says lead researcher Mark Reid. “Previously we thought Andromeda was dominant, and that we were the little sister of Andromeda,” Reid said. “But now it’s more like we’re fraternal twins” [AP]. But although the estimate gives our galaxy some new bragging rights, it’s not all good news. Being bigger means the gravity between the Milky Way and Andromeda is stronger. So the long-forecast collision between the neighboring galaxies is likely to happen sooner and less likely to be a glancing blow, Reid said [AP]. Luckily, that collision still isn’t expected for 2 to 3 billion years.

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A supernova first observed in the 16th century by Danish astronomer Tycho Brahe has been sighted again, astronomers report. Brahe observed its direct light but “light echoes” from the supernova that took a long detour around the universe have finally made it to Earth and have been captured by the Subaru Telescope in Hawaii. The new observations confirm that the supernova was the explosion of a white dwarf star. “Using light echoes in supernova remnants is time-traveling in a way, in that it allows us to go back hundreds of years to observe the first light from a supernova event,” said Tomonori Usuda, lead project astronomer at Subaru [Space.com].

In November 1572, Brahe noted a new shimmer in the night sky and thought it was the birth of a new star. But the shimmer disappeared 16 months later and some claimed it was a comet. Only in the early 20th century did astronomers understand that the fleeting brightness was a supernova and represented not the birth but the death throes of a star. The direct light from the supernova swept past Earth long ago. But some of it struck dust clouds in deep space, causing them to brighten [AP]. These light echoes are what astronomers have now captured and reported in Nature [subscription required]. “What we have essentially done here is to use interstellar dust as a kind of a mirror,” says [co-author] Oliver Krause [Nature News].

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For the first time, carbon dioxide has been detected in the atmosphere of an exoplanet, astronomers working with the Hubble Space Telescope report. Although the Jupiter-sized planet, which closely orbits the star HD 189733 about 63 light-years from Earth, is much too hot to support life, scientists are hailing the discovery as an exciting technical achievement. “In that context, the carbon dioxide measurement constitutes a dress rehearsal …for our long-term goal of trying to detect signs of life or signs of habitability on terrestrial-mass planets or super Earths in the habitable zone,” [Science News] says Mark Swain of NASA’s Jet Propulsion Laboratory.

Researchers deduced the presence of carbon dioxide by measuring the planet’s light spectrum with the Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS). To isolate the light spectrum coming from the planet, researchers used a method known as “secondary transit.” This involves recording the light spectrum of the planet and its star, and then measuring the spectrum of the star alone while the planet is hidden behind it. The difference of the two spectra is the spectrum of the light coming directly from the planet [Nature News]. Unlike previous measurements that focused on the mid-infrared range, NICMOS took measurements in the near-infrared range, enabling detection of the carbon dioxide signature.

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In news that has thrown astronomers and space enthusiasts into a tizzy of excitement, two separate research teams announced today that they have taken the first pictures of exoplanets, planets orbiting stars beyond the edge of our solar system. It’s an achievement that has long been considered vital in the search for planets like our own [Physics World].

One team spotted a single planet circling a bright star only 25 light-years away in the constellation Piscis Austrinus, while the other detected three giant planets orbiting a star 130 light-years away in the Pegasus constellation.

More than 300 so-called extrasolar planets have been found circling distant stars, making their discovery the hottest and fastest growing field in astronomy. But the observations have been made mostly indirectly, by dips in starlight as planets cross in front of their home star or by wobbles they induce going by it. Astronomers being astronomers, they want to actually see these worlds, but a few recent claims of direct observations have been clouded by debates about whether the bodies were really planets or failed stars [The New York Times]. But these newly discovered celestial objects are the right size for planets, and were observed moving around their parent stars.

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The Fermi Gamma-ray Space Telescope may have just gotten a hint in its hunt for the mysterious dark matter that is thought to make up the bulk of the universe’s mass. A group of astrophysicists has run a simulation of the distribution of dark matter in a galaxy like our Milky Way, and say that if the telescope scans the right region of space it may be able to detect gamma rays given off by collisions between the particles that are thought to make up dark matter (which have never been directly detected, and are still speculative).

Previously, some cosmologists have proposed that the best chance of a detection lies in nearby dwarf galaxies, since they should contain dense nuggets of dark matter that could be relatively easy to pinpoint. But a new study argues that a diffuse dark matter ‘halo’ surrounding the Milky Way offers an even better shot at glimpsing the mysterious stuff. “I would bet on it,” says lead author Volker Springel…. “And I’d be willing to risk a bit of money as well” [New Scientist].

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After several weeks of remote-control repair work, the Hubble Space Telescope is back in action, and is once again taking breathtaking images of distant galaxies. Today, NASA released an image which it called a “perfect 10″ because the paired galaxies resemble the number 10. The picture was released this morning by NASA to demonstrate that the observatory’s workhorse Wide Field Planetary Camera 2 is on the job again [Baltimore Sun], and a happy NASA press release added that the camera scored a perfect 10 for both its performance and the beautiful results.

The image shows a pair of galaxies, known as Arp 147, which are about 400 million light years away from Earth. The two galaxies are thought to have collided, and the image shows that aftermath. The blue ring was formed after the galaxy on the left passed through the galaxy on the right. Just as a pebble thrown into a pond creates an outwardly moving circular wave, or ripples, an outwardly propagating ring of higher density was generated at the point of impact of the two galaxies, astronomers explained. As this excess density collided with outer material that was moving inwards due to the gravitational pull of the two galaxies, shocks and dense gas were produced, stimulating star formation [SPACE.com].

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The nearest planetary system to our own has two asteroid belts in addition to a previously known ice belt, according to the latest observations by NASA’s Spitzer Space Telescope. The location and structure of the asteroid belts relative to the system’s central star, Epsilon Eridani, suggests the existence of earth-like planets. “We certainly haven’t seen it yet, but if its solar system is anything like ours, then there should be planets like ours,” says astronomer Massimo Marengo of the Harvard-Smithsonian Center for Astrophysics [USA Today].

The Epsilon Edidani system has long been of interest to astronomers and science fiction fans alike because of its proximity (10.5 light-years) and resemblance to our solar system. The newly discovered asteroid belts give the system an appearance even more like our own. The inner asteroid belt looks identical to ours in terms of material, and it orbits at 3 astronomical units (AU) from Epsilon Eridani — the same distance between the sun and the rocky asteroid belt between Mars and Jupiter. (An astronomical unit equals the average Earth-sun distance of 93 million miles, or about 150 million km.) Epsilon Eridani’s second asteroid belt is 20 AU from the star, or about where Uranus is in relation to our sun, and it is crowded with as much mass as Earth’s moon [Science News]. The outer asteroid belt was captured directly by Spitzer’s infrared cameras and the inner asteriod belt, though too far from the cameras, was indicated by the thermal energy from its infrared emissions.

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Just yesterday, the NASA engineers who are working on a remote-controlled reboot of the malfunctioning Hubble Space Telescope were thrilled with their progress: “Everything’s going perfectly,” a NASA spokeswoman said, and she estimated that the telescope would resume sending science data back to earth today. But today NASA reported that engineers had run into a problem while powering up the system after its reboot.

After the Hubble’s main data handling computer went on the fritz in late September, engineers devised a plan to switch over to the telescope’s “Side B” backup computer, which had been dormant for 18 years. NASA said yesterday that the backup system was successfully brought up, and that the only task that remained was testing and calibrating the telescope’s scientific instruments to ensure they were working properly with the new computer. However on Friday NASA posted a notice on its website saying “the activation of the telescope’s science instruments and resumption of observations has been suspended following two anomalies seen in systems on the telescope Thursday” [Reuters].

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The Fermi Gamma-ray Space Telescope only settled into its orbit a few months ago, but it’s already producing results that are delighting astronomers. Yesterday, NASA announced that Fermi had found a strange pulsar (a fast-spinning neutron star) by detecting only the gamma rays it emits. This is a first, NASA explains. Although astronomers have catalogued nearly 1800 pulsars, this is the first pulsar that seems to emit only gamma-ray radiation. Most other pulsars have been found using radio telescopes, although some also beam energy in visible light and X-rays [New Scientist].

Neutron stars are the small and incredibly dense bodies formed when massive stars explode into supernovas; perhaps the oddest of neutron stars are pulsars, which send out jets of radiation from their magnetic poles that sweep across Earth’s line of sight as the star spins on its axis. The newfound pulsar, which sits 4,600 light-years away in the constellation Cepheus, rotates at about a million miles an hour, and its beam of gamma rays reaches Earth about three times a second [National Geographic News]. Pulsars are often compared to lighthouses for the way their beams flash across our telescopes (see NASA animation).

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NASA has good news for fans of the spectacular stellar images produced by the Hubble Space Telescope, which has been unable to send data back to earth since a computer malfunctioned several weeks ago: Engineers have successfully powered up the Hubble’s backup data handling computer, which has slumbered in a dormant deep-freeze for the Hubble’s 18 years of operation, and NASA officials say the telescope should be sending scientific data again by tomorrow.

Engineers switched on the “Side B” backup system late Wednesday night. The engineers then briefly switched back on several of Hubble’s instruments — the Advanced Camera for Surveys, the Wide Field Planetary Camera 2 and the Near Infrared Camera and Multi-Object Spectrometer — to ensure that each had a working interface with the duplicate unit. The instruments were then commanded back into a dormant “safe mode,” in which they were hibernating since the observatory went silent [Science News].

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Tomorrow NASA engineers will begin a challenging remote-control fix of the malfunctioning Hubble Space Telescope; if all goes well, the Hubble should regain the capacity to send breathtaking stellar images back to Earth by Friday. The breakdown of a data-handling computer two weeks ago left the telescope crippled and unable to send data from its instruments; it also caused NASA to postpone its Hubble upgrade mission from October to sometime next February or so. The delay is costing NASA about $10 million a month, officials said [AP].

The fix requires powering down the entire telescope into “safe mode” and then turning on a backup data-handling system that has never been activated in the Hubble’s 18 years of space flight. Says Hubble manager Art Whipple: “It’s probably not unlike what an IT professional might do with an office network” [BBC News]. While NASA officials say there’s always a chance that the backup system won’t work, they also say they expect everything to go as planned. Says Whipple: “There’s very little ageing that goes on with an unpowered component in space,” he said. “It’s actually a very benign storage environment” [Reuters].

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A breakdown aboard the orbiting Hubble Space Telescope will delay the final space shuttle mission to upgrade and repair the aging telescope, which was scheduled to launch on October 14. NASA said today that the malfunction of a command and data-handling system means the telescope is unable to capture and beam down the data used to produce its stunning deep space images for which the Hubble is famous [Orlando Sentinel]. NASA officials said that system can’t be fixed remotely but added that they’re currently trying to activate a backup system.

The space shuttle Atlantis is already on the launch pad at Kennedy Space Center in preparation for its trip to the Hubble, but NASA says the unexpected glitch may delay the shuttle’s mission until early next year. Whenever Atlantis does fly, NASA may send up a replacement part for the failed component. It would take time to test and qualify the old replacement part and train the astronauts to install it in the telescope, said NASA spokesman Michael Curie. NASA also would have to work out new mission details for the astronauts who have trained for two years to carry out five Hubble repair spacewalks [AP].

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Astronomers think they have taken the first picture ever of a planet orbiting a star very similar to our own sun. However, the new planet itself appears to be quite different from our Earth. Located around 500 light-years from Earth, the planet in the snapshot is around eight times bigger than Jupiter, the biggest in our solar system and lies more than ten times further from its star than the sun does from Neptune [Telegraph]. Researchers were surprised to discover that the planet orbits at such a distance from its star, and say the discovery could upend accepted theories of planet formation.

The researchers say they’ll keep studying the object they spotted to confirm that the planet is in fact orbiting around the star, as opposed to the possibility, however unlikely, that the two objects just happen to lie in the same area of the sky at roughly the same distance from us. “Of course it would be premature to say that the object is definitely orbiting this star, but the evidence is extremely compelling,” [lead researcher David] Lafrenière said [SPACE.com].

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