Milky Way's Big Black Hole Gets Downsized. The black hole that lies at the heart of our galaxy is much smaller than previously known. It could fit within the space between the Earth and the Sun, according to a new study. Black holes are massive objects so dense that not even light can escape their gravitational pull. Diameter estimates for one at the center of the Milky Way have ranged widely, from as small as the orbit of Mercury to as big as that of Pluto. Last year, researchers estimated it was as wide as Earth's orbit around the Sun.
The measurement was made using the Very Long Baseline Array (VLBA), a network of 10 radio telescopes spread out across the United States. The finding is detailed in the Nov. 3 issue of the journal Nature. Black kole or something else? Sgr A* is located at the center of the Milky Way Galaxy, about 26,000 light-years away. An alternative possibility, though one not likely in the view of most theorists, is that the object might be a cluster of millions of collapsed dead stars, called neutron stars. Why our galaxy's black hole is a picky eater. This image shows the X-Ray close-up of Sagittarius A*, the Milky Way's central black hole. Black hole at center of Milky Way ejects more than 99% of material for the 1% it capturesThis has to do with temperature and angular momentum of gas in its surroundingsIn the early universe, there was a greater abundance of cold, dense gas (CNN) -- You might think of black holes as indiscriminate eaters, hungrily gobbling up everything in their vicinity.
But the black hole at the center of our Milky Way galaxy, Sagittarius A*, is not exactly like this, new research suggests. Instead, this black hole -- and likely other black holes in the centers of galaxies -- must spit out a lot in order to swallow a little. It's been a mystery why black holes at the centers of galaxies in the present universe appear so much dimmer than quasars, extremely bright objects from the early universe that have black holes at their centers, too. So what's going on? Why is that the case? Black Hole Grabs Planet-Sized Snack. SEATTLE--An ancient X-ray outburst from the supermassive black hole at the center of our Milky Way galaxy caused surrounding gas clouds to glow brightly in a cosmic light show that is only now being detected. The output likely involved the consumption of a snack equal in mass to the planet Mercury, researchers said here yesterday at the 209th meeting of the American Astronomical Society. Called Sagittarius A*, the supermassive black hole at the Milky Way's core is located some 27,000 light-years away and has an estimated mass of about three million suns.
It is surrounded by several massive iron-rich gas clouds that glow and emit their own X-rays when struck by photons or electrons [image]. No X-ray telescopes were in place when light from the black hole outburst first began to reach Earth about 60 years ago, but astronomers deduced the event based on "light echoes" from the clouds recently recorded by NASA's Chandra X-ray Observatory. Echoes of a meal Strangely calm. Odd Star Reveals Magnetic Field Around Milky Way's Monster Black Hole. A strange, pulsing star has revealed a powerful magnetic field around the giant black hole at the heart of Earth’s Milky Way galaxy, scientists say.
The finding may help shed light on how the galaxy's supermassive black hole devours matter around it and spits out powerful jets of superhot matter, the researchers added. The center of virtually every large galaxy is suspected to host a supermassive black hole with a mass that can range from millions to billions of times the mass of the sun.
Astronomers think the Milky Way's core is home to the monster black hole called Sagittarius A* — pronounced "Sagittarius A-star" — that is about 4 million times the mass of Earth's sun. [No Escape: How Black Holes Work (Infographic)] Scientists want to learn more about how black holes distort the universe around them, hoping to see if the leading theory regarding black holes, Einstein's theory of general relativity, holds up or if new concepts might be necessary. Pulsar tells the tale. Astronomers Surprised: Stars Born Near Black Hole. Black holes are best known for ripping stars apart, but new observations of the supermassive black hole at the center of the Milky Way show that it's actually helping stars form.
Until now, scientists had disagreed about the origin of a collection of massive stars orbiting less than a light-year from our galaxy's central black hole, which scientists call Sagittarius A*. The stars were first seen by infrared telescopes. The new finding, based on observations from the Chandra X-ray Observatory, confirms the theory that black holes can help form massive stars and gives more support to the idea that black holes play a big role in galaxy formation.
"In one of the most inhospitable places in our galaxy, stars have prevailed," said study co-author Sergei Nayakshin of the University of Leicester. "It appears that star formation is much more tenacious than we previously believed. " Mystery remains Astronomers still need to figure out how the process works.
No migration. A Quest to See a Black Hole's Shadow. At the core of the Milky Way is a supermassive black hole that sucks in light, rendering it virtually invisible. But astronomers say they will be able to see the black hole's overall shadow within a few years. "The Holy Grail of black hole astronomy is within our grasp," says Avery Broderick of the Harvard-Smithsonian Center for Astrophysics. "We could see the shadow that the black hole casts on surrounding material, and determine the size and spin of the black hole itself. " Nothing can escape the intense gravitational field of a black hole, not even light.
And since they can't emit light, or any other form of matter, there's no visible evidence of their existence. Some of this radiation escapes and can be detected. Astronomers have already detected radiation from hot spots just outside the black hole, and they believe that these will paint a background against which the black hole's profile, or shadow, will stand out. Black hole at heart of our galaxy “will erupt next year”, say astronomers. A huge eruption lit up the skies on our planet two million years ago - creating a fuzzy ball of light around the size and brightness of the moon. The eruption - a huge blast from the black hole at the centre of our galaxy - would have been witnessed by our ancestors, homo erectus, on the plains of Africa. Scientists have found the first evidence of this “huge explosion” of radiation from the supermassive black hole - four million times the mass of our sun - a faint glow in a cloud of gas millions of miles from the black hole itself.
Scientists describe the supermassive black hole - Saggitarius A* - as a “dormant volcano”. Blasts of energy can jet out of black holes when stars and gas clouds are “consumed” by the black hole - and scientists warn that there are “lots and lots” circling our galactic centre. One in particular could erupt next year. [Solar sails to "carry mankind to the stars"] The evidence comes from a lacy filament of gas, mostly hydrogen, called the Magellanic Stream. Milky Way's Black Hole to Swallow Giant Cloud Soon. The colossal black hole at the center of our Milky Way galaxy will soon to get a big, tasty meal, astronomers say. A humongous gas cloud is on a collision course for the Milky Way's core — the home of Sagittarius A* (pronounced "Sagittarius A-star"), which scientists suspect is a supermassive black hole with the mass of 4 million suns. When the huge gas cloud arrives in the vicinity, which it will appear to us to do in mid-2013, it will surely be swallowed up by the hungry black hole, scientists say.
Astrophysicist Stefan Gillessen of the Max Planck Institute for Extraterrestrial Physics in Munich, Germany, has been observing the Milky Way's center for about 20 years. So far, he's seen only two stars come as close to Sagittarius A* as the cloud will. "They passed unharmed, but this time will be different: the gas cloud will be completely ripped apart by the tidal forces of the black hole," Gillessen said in a statement. Milky Way's Giant Black Hole Spits Out Its Food. The colossal black hole at the heart of the Milky Way galaxy is a messy eater. Of all the gas that falls toward the black hole, 99 percent gets spewed back out into space, new observations show, making the black hole akin to a toddler whose food ends up mostly on the floor, rather than his mouth.
The Milky Way's supermassive black hole, called Sagittarius A* (pronounced "Sagittarius A-star"), contains the mass of 4 million suns. Yet it's not getting much larger, according to the new findings, which help explain why the object is surprisingly dim. Although black holes themselves can't be seen, their immediate vicinities usually emit strong radiation from the material falling into them. "There's been a debate for the last 20 years or so about what actually is happening to the matter around the black hole," said research leader Q. 3 million seconds "Exactly how it happens is not totally clear," Wang told SPACE.com. Ruled out theories Stay tuned!
Milky Way's Supermassive Black Hole Caught Eating..Something | Video. The giant black hole at the center of our galaxy has exploded before and will explode again. Lurking at the heart of the Milky Way is a supermassive black hole more than four million times the mass of the Sun. Despite its monstrous proportions, this black hole is peaceful — almost placid. However, a recent analysis by astronomers at Mount Stromlo Observatory and the University of Colorado seems to indicate the black hole, known as Sagittarius A* (pronounced Sagittarius A Star) is hiding a violent side. Just two million years ago it may have erupted in an explosion so enormous that gas clouds 200,000 light years away are still glowing like the embers from a recently extinguished fire. If accurate, the same thing could happen again at any time.
With virtually no matter falling into it, Sagittarius A* managed to hide from astronomers for a long time. In 1996 astronomers became aware of an eerie glow emanating from the Magellanic Stream, a wisp of gas trailing the Milky Way’s satellite galaxies, the Large and Small Magellanic Clouds. What does this mean for Earth? Homing In On Black Holes.
Scientists Closing in on Black Hole at Center of Our Galaxy | Sagittarius A* Though scientists have suspected for a while that a giant black hole lurks at the center of our galaxy, they still can't say for sure it's the explanation for the strange behavior observed there. Now researchers are closer than ever to being able to image this region and probe the physics at work – potentially shedding light on the great conflict between the theories of general relativity and quantum mechanics. At the heart of the Milky Way, astronomers see some wacky things. For example, about a dozen stars seem to be orbiting some invisible object. One star has been found to make a 16-year orbit around the unseen thing, moving at the hard-to-imagine speed of about 3,000 miles (5,000 kilometers) a second.
By comparison, the sun moves through space at a comparatively glacial 137 miles (220 kilometers) a second. Based on the laws of motion, these dozen stars' orbits should be caused by the gravitational pull of some massive object in the center of the galaxy. Looking closer. Center of Attention: Space Telescope May Hone in on Heart of the Milky Way in Hunt for Dark Matter. NASA’s premier gamma-ray space telescope may be changing tack in the coming months from an equal-opportunity scan of the whole sky to a pattern that prioritizes the center of our Milky Way galaxy. The new strategy could help the Fermi telescope find more spinning stars called pulsars, observe a cloud on a collision course with the galaxy’s supermassive black hole and, just maybe, find evidence of dark matter. In March 2013, after five years of business as usual, the Fermi team put out a call for alternative observing strategies.
Five proposals came in, and in August a review panel convened to discuss the ideas. Ultimately, the panel recommended a new strategy based on a proposal to prioritize observing the galactic center. Until now, Fermi has covered the full sky every three hours. Under the new plan, the telescope would still scan every spot on the sky at least once a day, but would favor the center of the galaxy, building up better statistics on its measurements there. Black Hole Spits X-Rays From Our Galaxy's Core | Video. Andreas Müller - Das größte Schwarze Loch der Milchstraße. Pdf Einleitung Im Wissensportal für Astrophysik widmet sich ein umfangreicher Artikel der Physik Schwarzer Löcher. Ein weiterer Artikel beschäftigt sich mit der Rolle Schwarzer Löcher in der gängigen Vorstellung von Aktiven Galaktischen Kernen (AGN). In diesem Artikel geht es um das 'Monster in unserer Heimatgalaxie': einem supermassereichen Schwarzen Loch inmitten der Milchstraße! Die Hypothese Diese an sich abenteuerliche Behauptung ist durch folgenden Sachverhalt motiviert: Ein supermassereiches Schwarzes Loch (engl. supermassive black hole, kurz SMBH) ist das Schlüsselelement im Standardmodell aktiver Galaxien: die extreme AGN-Leuchtkraft von bis zu 100 Billionen Sonnen kann nur durch ein Materie aufsammelndes Schwarzes Loch erklärt werden.
Was haben aktive Galaxien mit der offensichtlich inaktiven Milchstraße zu tun? Struktur der Milchstraße Scheibe und Halo Wir verschaffen uns zunächst einen Überblick über das 'Gebilde Milchstraße'. Spiralarme und Sternentstehungsregionen. Monster of the Milky Way HD. Supermassive Black Holes. Black Holes.