Astronomers might need to adjust their expectations for black holes. According to the New York Times, an international research team has determined that Cygnus X-1, one of the first discovered black holes, is considerably more massive than once thought. The binary-system based hole was originally pegged at ‘just’ 15 solar masses, but is now believed …
Larger black holes may be the usual attention-getters, but the smaller ones may be at least as important. A team using the Hubble Space Telescope has discovered a concentration of small black holes in the NGC 6397 globular star cluster (pictured above) 7,800 light-years away — the first to have its mass and extent recorded. …