For a star of this size, a nonexplosive collapse would be expected, he says, "and this is probably the strongest case." Still, Fryer thinks that only about one in 10 black holes should form in this way, because most stars are less massive-and far more likely to detonate. Given the stars estimated mass before its disappearance, it could have created a black hole measuring 85 to 120 times the mass of Earths sun, though how this could have happened without a. The argument is convincing, says supernova modeler Chris Fryer of Los Alamos National Laboratory in New Mexico. When the star died, its remaining gas vanished silently into a black hole of about 10 solar masses. The original star probably contained between 40 and 100 times our sun's mass and then lost most of it during intense winds, he says. Stars with masses greater than about ten solar masses are thought to end their lives either in a supernova1 or in a direct gravitational collapse process2. ![]() A bigger boom would have booted the binary system at higher speed-and probably not in the same direction as its peers, Mirabel notes. His calculations show that the parent star ejected no more than one sun's worth of mass when the black hole formed-far too small for a supernova blast. This binary system, called Cygnus X-1, appears to be part of an association of massive stars drifting through the Milky Way at about the same pace, Mirabel says. His group's newest discovery, published online 24 April in Science, reveals the opposite: a binary poking along at a sluggish 9 kilometers per second. Recently, Mirabel detected one binary jetting through space at 120 kilometers per second-a sure sign that a supernova drastically boosted its speed ( ScienceNOW, 19 November 2002. X-rays and radio waves from the hot gas pinpoint the holes. Félix Mirabel of the French Atomic Energy Commission in Saclay and colleagues have observed the motions of binary systems in which suspected black holes rip gas off companion stars. To trace the origins of black holes in our galaxy, astronomer I. Until now, astronomers had no firm evidence that was true. ![]() However, models predict that rare stars at least 40 times heftier than our sun should plummet directly into black holes without exploding, because their massive outer layers snuff the shock wave like the heavy lid of a pressure cooker. If the collapsing core is a few times the mass of our sun, gravity will crush it into an infinitely dense speck. The star's core collapses, igniting a shock wave that blasts the rest of the star into space. Astronomers have found one of them drifting so slowly through space that they believe its parent star morphed into a black hole without blowing up.Īccording to theory, a black hole arises when a giant star runs out of fuel for thermonuclear fusion. But a rare breed of black hole may enter the universe with a phffft, not a boom. Supernovas, the explosive deaths of massive stars, often herald the births of black holes.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |