It was only two weeks ago that astronomers found that what they had previously thought about black holes, was not the entire story. Announced on the 17th of October, a "stellar" black hole was discovered to be 16 times the mass of our own sun. Previously it was thought that the norm was only 10. That record has been smashed, by a new stellar black hole that is weighing in at 24 times the mass of our sun.
We know the basics of the black hole story; giant gaping hole in space, sucks in all matter from around it, doing god-knows what with it. They are also invisible to observation, due to the fact that they also suck in light; that which we see by.
What you may not know is that there is more than just one type of black hole.
Black holes come in "supermassive", "intermediate-mass", "stellar-mass" and "micro", from largest to smallest.
The black holes in question at the moment are stellar-mass black holes, and are created during the last throes of life of massive stars which collapse in on themselves. As mentioned, these black holes have generally come in at 10 solar masses, but have twice been proven wrong in the space of a few weeks.
"We weren't expecting to find a stellar-mass black hole this massive," said study team member Andrea Prestwich of the Harvard-Smithsonian Center for Astrophysics in Cambridge. "It seems likely that black holes that form from dying stars can be much larger than we had realized."
Detailed in the most recent edition of the journal Astrophysical Journal Letters, it is located in a neighboring system, the dwarf galaxy IC 10, sitting some 1.8 million light years from Earth, amidst the constellation Cassiopeia.
The two recent discoveries shared a similar method of discovery. Both are orbiting around a companion star. Thus, every time the star was in the way it would block off the X-Rays given off by the black hole. The changes in the brightness of X-Rays given off were detected in Nov. 2006 by NASA's Chandra X-ray Observatory.
Follow up observations, studied by Prestwich's team, provided them with speed and mass data. As for the preliminary mass of 24 solar masses? "Future optical observations will provide a final check," Prestwich said. "Any refinements in the IC 10 X-1 measurement are likely to increase the black hole's mass rather than reduce it."
As rare and unusual as these two recent discoveries have proved, they still pale in comparison when compared to the supermassive black holes believed to be lurking at the heart of massive galaxies. Such black holes can have masses of million to billion times that of our own sun
Joshua Hill, a Geek’s-Geek from Melbourne, Australia, Josh is an aspiring author with dreams of publishing his epic fantasy, currently in the works, sometime in the next 5 years. A techie, nerd, sci-fi nut and bookworm.
