By Ron Cowen
Two teams of astronomers reported this week that they had confirmed the existence of a new class of black hole.
Most astronomers now accept the reality of black holes, objects whose immense gravity sucks in everything around them. Observations have indicated that these gravitational monsters come in two sizes: baby black holes just a few times more massive than the sun and supermassive black holes weighing as much as a billion suns. In contrast, the newly found class consists of middleweights, ranging between 100 to 10,000 times the mass of the sun.