nov 232013
Anne's Image of the Day: Spiral Galaxy NGC 7424

November 23, 2013 NGC 7424, a barred spiral galaxy in Grus Image Credit: ESO NGC 7424 is a barred spiral galaxy of some 100,000 light-years across, located about 37.5 million light-years away from Earth in the southern constellation of Grus (the Crane), while it is receding from us at approximately 939 kilometers per second. It [continue reading]

mei 062012
Mystery X-ray source in distant galaxy - video

  Since the 1980s, astronomers have known about a mysterious class of objects that they call “ultraluminous X-ray sources,” or ULXs. They named them this because these objects give off more X-rays than most other binary star systems where black holes or neutron stars are in orbit around a normal companion star. Recently, scientists using [continue reading]

mei 012012
NASA's Chandra Sees Remarkable Outburst From Old Black Hole

  An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. The discovery, made by astronomers using NASA’s Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy [continue reading]

feb 232012
First ultraluminous source in Andromeda galaxy unmasked as stellar mass black hole

Detailed observations show that the first ultraluminous X-ray source detected in our neighbouring Andromeda galaxy is due to a stellar mass black hole swallowing material at very high rates. An international team of astronomers, including scientists at the Max Planck Institute for Extraterrestrial Physics, have now published their findings in two papers. The emission of [continue reading]