色情视频

For decades, Cygnus X-1 has been home to the black hole that you read about in textbooks. A black hole by NASA鈥檚 definition is 鈥渁 place in space where gravity pulls so much that even light cannot get out.鈥� 

Though Cygnus X-1 has long been the most referenced example of a black hole, ironically there wasn鈥檛 much known about it 鈥� until now. 

色情视频 astronomy professor Jerome Orosz is the author of one of three papers in the December issue of the Astrophysical Journal, which reveals striking new information about Cygnus X-1, piecing together a more defined picture of this deep dark spot in space.

鈥淭hese new data are a huge improvement over what was previously known about Cygnus X-1,鈥� Orosz said. 

鈥淲hile it has long been suspected that Cygnus X-1 contains a black hole and not a neutron star or white dwarf, the precise mass of the black hole was not known previously. We now know the distance from Earth, the mass of the black hole and how quickly it spins, all with uncertainties of less than 10 percent.鈥�

Light years away

The first paper authored by researchers at the Harvard-Smithsonian Center for Astrophysics presented observations that allowed an accurate distance measurement to be made. Cygnus X-1 is 6,070 light years away, with an uncertainty of only 400 light years.

鈥淭hat鈥檚 a long way 鈥� even by Star Trek standards,鈥� Orosz said. 鈥淚deally, you would want to fly there in a space ship and poke around, but obviously that鈥檚 impossible.鈥�

鈥淭hat鈥檚 a long way 鈥� even by Star Trek standards.鈥�

The second paper, of which Orosz was the lead author, calculated the mass of the black hole and discovered it is approximately 15 times the mass of the sun. 

鈥淭he precise distance measurement made it possible for us to pin down the black hole mass,鈥� Orosz said. The third paper, also by researchers at the center, details the measurement of the spin of the black hole using X-ray observations from space.

鈥淲ith the mass determined, we were able to calculate the spin of the black hole which was found to be about 800 revolutions per second,鈥� Orosz said.

In the beginning

Orosz said this finding helps to shed new light on the origin of the black hole in Cygnus X-1.

鈥淭he black hole appears to have been formed with high rate of spin. In addition, it may have formed through a direct collapse of the core of a massive star, rather then through a more spectacular supernova explosion.鈥�