Friday, April 04, 2008
NASA: a pocket black hole found
But don't expect the Hawking radiation to be observed soon. The diameter of the spherical event horizon is 24 kilometers: that's about the wavelength of its would-be thermal radiation. ;-) Using the identity "R = 2GM/c2", you can check that the mass of the black hole equals 3.8 solar masses. The previous record diet black hole in GRO 1655-40 had 6.3 Suns.
We are probably getting to the lower limit on masses that can be naturally produced by the collapse of a star. The boundary is probably somewhere between 1.7 and 2.7 solar masses.
Sorry, I don't have an English version of this videoclip, so here is the Czech one. ;-) They also say that streams of energy are everywhere around. Black holes are born when stars collapse. Light cannot escape. Strong X-rays around help to create stars and they kill all the life that would dare to interfere with their trajectories.