NASA | X-ray Nova Reveals a New Black Hole in Our Galaxy
Sign in to YouTube
Sign in to YouTube
Sign in to YouTube
Published on Oct 5, 2012
On Sept. 16, NASA's Swift satellite detected a rising tide of high-energy X-rays from a source toward the center of our Milky Way galaxy. The outburst, produced by a rare X-ray nova, announced the presence of a previously unknown stellar-mass black hole.
An X-ray nova is a short-lived X-ray source that appears suddenly, reaches its emission peak in a few days and then fades out over a period of months. The outburst arises when a torrent of stored gas suddenly rushes toward one of the most compact objects known, either a neutron star or a black hole.
Named Swift J1745-26 after the coordinates of its sky position, the nova is located a few degrees from the center of our galaxy toward the constellation Sagittarius. While astronomers do not know its precise distance, they think the object resides about 20,000 to 30,000 light-years away in the galaxy's inner region. The pattern of X-rays from the nova signals that the central object is a black hole.
Ground-based observatories detected infrared and radio emissions, but thick clouds of obscuring dust have prevented astronomers from catching Swift J1745-26 in visible light.
The black hole must be a member of a low-mass X-ray binary (LMXB) system, which includes a normal, sun-like star. A stream of gas flows from the normal star and enters into a storage disk around the black hole. In most LMXBs, the gas in the disk spirals inward, heats up as it heads toward the black hole, and produces a steady stream of X-rays.
But under certain conditions, stable flow within the disk depends on the rate of matter flowing into it from the companion star. At certain rates, the disk fails to maintain a steady internal flow and instead flips between two dramatically different conditions -- a cooler, less ionized state where gas simply collects in the outer portion of the disk like water behind a dam, and a hotter, more ionized state that sends a tidal wave of gas surging toward the center.
This phenomenon, called the thermal-viscous limit cycle, helps astronomers explain transient outbursts across a wide range of systems, from protoplanetary disks around young stars, to dwarf novae - where the central object is a white dwarf star - and even bright emission from supermassive black holes in the hearts of distant galaxies.
This video is public domain and can be downloaded at: http://svs.gsfc.nasa.gov/goto?11108
Like our videos? Subscribe to NASA's Goddard Shorts HD podcast:
Or find NASA Goddard Space Flight Center on facebook:
Or find us on Twitter:
Standard YouTube License
- 3:09 10 Strange Unexplained Eventsby Alltime10s Featured 1,467,081
- 3:28 NASA | Colliding Neutron Stars Create Black Hole and Gamma-ray Burstby NASA Goddard150,312 views
- 2:34 NASA | Gradient Sunby NASA Goddard143,608 views
- 4:17 NASA | Fiery Looping Rain on the Sunby NASA Goddard906,211 views
- 2:42 NASA | Evolution of the Moonby NASA Goddard3,293,184 views
- 56:45 The Ultimate Guide to Black Holesby SUPERIOR HISTORY371,194 views
- 24:59 The Largest Black Holes in the Universeby SpaceRip1,907,842 views
- 45:58 National Geographic - Monster Black Holesby The Movie Club229,274 views
- 10:45 Travel INSIDE a Black Holeby Vsauce5,683,861 views
- 5:40 The Largest Galaxy in the Universe: IC 1101by Deep Astronomy1,142,580 views
- 5:20 NASA: Amazing Experiments with Water in Zero Gravityby TV ADDICT4,448,260 views
- 25:12 When Will Time End?by SpaceRip905,299 views
- 16:58 NASA WTF Did You Do To Piss Off E.T - STS107 I Want ANSWERS On This One 11-21-2013by DarkSkyWatcher74268,245 views
- 57:53 (HD) Swallowed by a BLACK HOLE - Full Documentaryby VaurSechs91,683 views
- 3:19 Earth 100 Million Years From Nowby SpaceRip6,596,381 views
- 25:01 Mysteries of a Dark Universeby SpaceRip533,169 views
- 2:26 NASA Scientist Says Warp Drive is Doableby NewsyScience268,264 views
- 57:53 Swallowed by a Black Hole(full documentary)HDby Nature + Science Documentaries84,528 views
- 2:48 10 Mind-Bending Facts About Black Holesby Alltime10s815,382 views
- 1:43 If the Moon were replaced with some of our planetsby yeti dynamics2,785,634 views
- Loading more suggestions...