okt 042012
 
Surprise: Two Black Holes in One Globular Star Cluster

  An unexpected discovery by an international team of astronomers is forcing scientists to rethink their understanding of the environment in globular star clusters, tight-knit collections containing hundreds of thousands of stars. Two black holes in a globular star cluster. Image Credit: The University of Southampton The astronomers, including Dr Tom Maccarone from the University of [continue reading]

jul 062012
 
The First "Middleweight" Black Hole is Found

  Observations with CSIRO’s Australia Telescope Compact Array have confirmed that astronomers have found the first known “middleweight” black hole. Galaxy ESO 243-49, about 300 million light-years away, is home to the newly found black hole. Credit: NASA, ESA and S. Farrell (University of Sydney) Outbursts of super-hot gas observed with a CSIRO radio telescope [continue reading]

apr 292012
 
X-ray Quasars, and a Distance Record

Quasars are thought to be galaxies whose bright nuclei contain massive black holes around which disks are actively accreting matter. The accretion process releases vast amounts of energy, often including a wind, and as a result quasars are among the most powerful energy sources known. Because they are so bright, quasars can be seen even [continue reading]

mrt 102012
 
NASA's RXTE captures thermonuclear behavior of unique neutron star

Caption: This graph based on RXTE data provides an overview of the changing character of T5X2’s X-ray emission during outbursts from Oct. 13 to Nov. 19, 2010. As the persistent X-ray emission rises (upward steps in the plot), the burst rate increases while the burst brightness decreases. The abrupt dropout on Oct. 13 occurred when [continue reading]