Archive
NASA’s Chandra Observatory Catches Giant Black Hole Rejecting Material
Aug. 29, 2013 — Astronomers using NASA’s Chandra X-ray Observatory have taken a major step in explaining why material around the giant black hole at the center of the Milky Way Galaxy is extraordinarily faint in X-rays. This discovery holds important implications for understanding black holes.
New Chandra images of Sagittarius A* (Sgr A*), which is located about 26,000 light-years from Earth, indicate that less than 1 percent of the gas initially within Sgr A*’s gravitational grasp ever reaches the point of no return, also called the event horizon. Instead, much of the gas is ejected before it gets near the event horizon and has a chance to brighten, leading to feeble X-ray emissions.
These new findings are the result of one of the longest observation campaigns ever performed with Chandra. The spacecraft collected five weeks’ worth of data on Sgr A* in 2012. The researchers used this observation period to capture unusually detailed and sensitive X-ray images and energy signatures of super-heated gas swirling around Sgr A*, whose mass is about 4 million times that of the sun.
Read more: http://www.sciencedaily.com/releases/2013/08/130829142311.htm
Voyager 1 Has Left the Solar System
Voyager 1 appears to have at long last left our solar system and entered interstellar space, says a University of Maryland-led team of researchers
Carrying Earthly greetings on a gold plated phonograph record and still-operational scientific instruments — including the Low Energy Charged Particle detector designed, built and overseen, in part, by UMD’s Space Physics Group — NASA’s Voyager 1 has traveled farther from Earth than any other human-made object. And now, these researchers say, it has begun the first exploration of our galaxy beyond the Sun’s influence.
“It’s a somewhat controversial view, but we think Voyager has finally left the Solar System, and is truly beginning its travels through the Milky Way,” says UMD research scientist Marc Swisdak, lead author of a new paper published online this week in The Astrophysical Journal Letters. Swisdak and fellow plasma physicists James F. Drake, also of the University of Maryland, and Merav Opher of Boston University have constructed a model of the outer edge of the Solar System that fits recent observations, both expected and unexpected.
Read more: http://www.sciencedaily.com/releases/2013/08/130815133726.htm
Largest Quasar Ever Discovered Burns 100 Times Brighter Than Entire Milky Way
Astronomers have found a galaxy whose super-luminous nucleus–called a quasar–is burning 100 times as much energy as the entire Milky Way galaxy.
Though theory has long predicted that quasars this powerful should exist, the newly-discovered object, known as SDSS J1106+1939, is by far the most energetic ever observed. The quasar is powered by a supermassive black hole that lies at its center.
Is NASA about to unveil plans for manned moon mission?
by Robert T. Gonzalez at http://io9.com/
Suit up, people — word is we’re heading back to the Moon.
According to space policy expert John Logsdon, there’s a decent chance NASA has already cleared plans to establish a manned base on the far side of the Moon with the Obama administration. Thing is, they’ve probably been keeping it under wraps in the event that Romney had won Tuesday’s election. Now that Obama has secured a second term, Logsdon says an accouncement from the Agency could be forthcoming.
“NASA has been evolving its thinking, and its latest charts have inserted a new element of cislunar/lunar gateway/Earth-moon L2 sort of stuff into the plan,” said Logsdon in an interview with SPACE.com’s Mike Wall.
“They’ve been holding off announcing that until after the election,” Logsdon added, noting that NASA’s mission, direction, and budget could have been revised under a Romney administration.
An announcement would certainly gel with the Obama administration’s ambitious agenda for space. In 2010, the President signed the NASA 2010 Authorization Act into law, freeing up close to $60 billion in NASA spending through 2013. This funding would serve as one of the first sparks in a plan to ignite a resurgence in space exploration, including an asteroid visit by 2025 and and a trip to Mars by the 2030s. A manned outpost at the Earth-moon L2 “gateway” — shown in the diagram below — could serve as an important stepping stone in our path out into the solar system.
NASA’s NuSTAR Spots Flare from Milky Way’s Black Hole
ScienceDaily (Oct. 23, 2012) — NASA’s newest set of X-ray eyes in the sky, the Nuclear Spectroscopic Telescope Array (NuSTAR), has caught its first look at the giant black hole parked at the center of our galaxy. The observations show the typically mild-mannered black hole during the middle of a flare-up.
“We got lucky to have captured an outburst from the black hole during our observing campaign,” said Fiona Harrison, the mission’s principal investigator at the California Institute of Technology (Caltech) in Pasadena. “These data will help us better understand the gentle giant at the heart of our galaxy and why it sometimes flares up for a few hours and then returns to slumber.”
The new images can be seen by visiting: http://www.nasa.gov/nustar .
Read more: http://www.sciencedaily.com/releases/2012/10/121023145224.htm
Milky Way Now Has a Twin (or Two): Astronomers Find First Group of Galaxies Just Like Ours
ScienceDaily (Aug. 22, 2012) — Research presented Aug. 23, 2012 at the International Astronomical Union General Assembly in Beijing has found the first group of galaxies that is just like ours, a rare sight in the local Universe.
The Milky Way is a fairly typical galaxy on its own, but when paired with its close neighbours — the Magellanic Clouds — it is very rare, and could have been one of a kind, until a survey of our local Universe found another two examples just like us.
Astronomer Dr Aaron Robotham, jointly from the University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR) and the University of St Andrews in Scotland, searched for groups of galaxies similar to ours in the most detailed map of the local Universe yet, the Galaxy and Mass Assembly survey (GAMA).
“We’ve never found another galaxy system like the Milky Way before, which is not surprising considering how hard they are to spot! It’s only recently become possible to do the type of analysis that lets us find similar groups,” says Dr Robotham.
Read more: http://www.sciencedaily.com/releases/2012/08/120822221342.htm
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