November 15, 2010

NASA Discovers Youngest Black Hole Neighboring Earth

NASA announced on Monday that its Chandra X-ray Observatory has discovered the youngest black hole known to exist in our cosmic neighborhood. 

The 30-year-old black hole, known as Supernova 1979C (SN 1979C), is about 51 million light years from Earth and occurred in galaxy M-100.  Chandra has revealed a bright source of X-rays that has remained steady during observation from 1995 to 2007.  This data suggests that the object is a black hole being fed either by material falling into it from the supernova or a binary companion.

"If our interpretation is correct, this is the nearest example where the birth of a black hole has been observed," said Daniel Patnaude of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. who led the study.

The scientists believe that SN 1979C formed when a star about 20 times more massive than the sun collapsed.

Many black holes are thought to form because of gamma-ray bursts (GRBs).  However, SN 1979C is different because it belongs to a class of supernovas unlikely to be associated with a GRB. 

SN1979C was a supernova type 2 linear, which is rare subclass of core-collapse supernova.  This type of supernova results from the internal collapse and violent explosion of a massive star.  A star must have at least 9 times the mass of the Sun in order to undergo this type of core-collapse.

"Only a small fraction of them probably produce black holes in their center," said Alex Filippenko, an astrophysicist from the University of Berkley.

NASA said at a press conference on Monday that they know of several dozen black holes in our Milky Way galaxy, but they do not know the ages. 

NASA said that SN 1979C is the nearest example where the birth of a black hole has been observed.

"This may be the first time the common way of making a black hole has been observed," said co-author Abraham Loeb, also of the Harvard-Smithsonian Center for Astrophysics. "However, it is very difficult to detect this type of black hole birth because decades of X-ray observations are needed to make the case."

It is also a possibility that SN 1979C is a young neutron star with a powerful wind of higher energy particles.  This would make SN 1979C the youngest and brightest example of such a "pulsar wind nebula" and the youngest known neutron star.  The Crab pulsar is about 950 years old.

"It's very rewarding to see how the commitment of some of the most advanced telescopes in space, like Chandra, can help complete the story," said Jon Morse, head of the Astrophysics Division at NASA's Science Mission Directorate.

Image Credits: X-ray: NASA/CXC/SAO/D.Patnaude et al, Optical: ESO/VLT, Infrared: NASA/JPL/Caltech (more information)   


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