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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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In a galaxy far, far away—11.1 billion light-years away, to be exact—researchers have discovered the telltale signature of water. The water molecules seem to be located in the galaxy’s center, where a supermassive black hole called a quasar is spewing out tons of radiation as material falls into it. The water molecules lie in clouds of dust and gas that feed the black hole, and appear to be amplifying radio waves at a specific frequency, forming what’s called a maser, or the radio equivalent of a laser [Wired News].

The quasar, called MG J0414+0534, is so far away that the light researchers are observing originated when the universe was only 2.5 billion years old. “We now know water is out there,” says Violette Impellizzeri from the Max Planck Institute (MPI) for Radio Astronomy in Bonn, Germany. “Because water masers arise close to the cores of galaxies, our result opens new interesting possibilities for studying supermassive black holes [at the galactic cores] at a time when galaxies were forming” [New Scientist].

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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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A sugar molecule essential to life as we know it has been found in the far reaches of the Milky Way, scientists report. Astronomers working with the IRAM radio dish array in France report the presence of glycolaldehyde—a simple sugar found in RNA—in a region of our galaxy known to churn out stars. The molecule appears to have formed with all of the other stuff that makes up planets, suggesting that many other worlds are seeded with some of life’s ingredients right from birth [ScienceNOW Daily News].

Glycoladehyde is a building block of ribose, a component of RNA. Many scientists believe RNA preceded DNA in vesting the earliest forms of life with reproductive capabilities; thus the finding of glycoladehyde has particular significance for those searching for extraterrestrial life. The astronomers detected radio and microwave signatures of glycolaldehyde within the core of what appears to be a coalescing disk of dust and gas in a star-forming region called G31.41+0.31, about 26,000 light-years away. The sugar molecule can apparently form in a simple reaction between carbon monoxide molecules and dust grains [ScienceNOW Daily News]. The astronomers believe the molecules they see are a few hundred thousand years old.

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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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An enormous helium balloon floating about 24 miles above Antarctica has detected a mix of high-energy electrons so exotic that researchers say the particles must have been created by some fascinating process: They may have been formed when dark matter particles collided and annihilated each other, or else a surprisingly close astronomical object like a pulsar could be spitting the electrons at Earth.

Researchers can’t yet determine which answer is correct, but say the dark matter explanation is more exciting. Dark matter is one of astrophysics’ greatest enigmas. It is thought to be five times more common than visible matter, but there is no proof of what it is made of. The existence of dark matter has largely been inferred from its gravitational effects, such as the fact that most galaxies have enough mass to remain as well-defined objects despite having too little visible matter to account for the necessary gravity [National Geographic News]. If the research balloon did detect the signature of dark matter through the particles left over from collisions, it would be the closest researchers have ever gotten to seeing the mysterious stuff.

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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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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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A starlit sky may look serene, but those stars are actually quivering and quaking; now, researchers have recorded the stellar vibrations of distant stars for the first time. The pulsations reflect changes in temperature caused when roiling heat makes the outer surface of the star vibrate. Portions of the surface expand and cool, while others contract and get warmer [New Scientist].

The initial discovery of oscillations in our Sun in the late 1970’s led to the creation of “solar seismology,” which has since been used to measure the movement and transport of heat around the Sun. Solar seismology led to rapid progress in understanding the Sun’s internal structure, but eventually researchers hit a wall [COSMOS]. For accurate measurements, researchers need a long stretch of uninterrupted observations, which is impossible from ground-based telescopes.

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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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In a bizarre finding that has disrupted the current understanding of the universe, astronomers have detected evidence of a massive gravitational force beyond the horizon of the observable universe. What’s being called a dark flow appears to be pulling vast clusters of galaxies toward a 20-degree-wide patch of sky between the constellations of Centaurus and Vela. “It does fly in the face of everything we know,” said astronomer Dale Kocevski…. “I’m sure it’s going to be controversial” [Discovery News].

When scientists talk about the observable universe, they don’t just mean as far out as the eye, or even the most powerful telescope, can see. In fact there’s a fundamental limit to how much of the universe we could ever observe, no matter how advanced our visual instruments. The universe is thought to have formed about 13.7 billion years ago. So even if light started travelling toward us immediately after the Big Bang, the farthest it could ever get is 13.7 billion light-years in distance. There may be parts of the universe that are farther away (we can’t know how big the whole universe is), but we can’t see farther than light could travel over the entire age of the universe [SPACE.com].

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Astronomers believe they’ve found evidence of a massive collision between two planets in a mature solar system, shaking theories that such pileups only occur in young systems where planetary orbits aren’t yet stabilized. Says lead researcher Benjamin Zuckerman: “It’s as if Earth and Venus collided with each other…. Astronomers have never seen anything like this before; apparently major, catastrophic, collisions can take place in a fully mature planetary system” [Reuters].

Researchers base their theory on observations of vast clouds of dust and debris in a binary star system 300 light years away in the Aries constellation. Initially, they had a different idea about why the system contains 1 million times more dust that our own solar system: They had assumed it was a young star, just a few hundred million years old, and the debris was leftovers from planet formation. But earlier this year, another study showed the star was actually a binary pair, and that the stars were billions of years old [SPACE.com]. That finding forced astronomers to rethink what could have caused the dust; in older systems, most debris has either been consolidated into planets or pushed away by solar winds.

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