NASA Astronomers Find Bizarre Planet-Mass Object Orbiting Neutron Star
Using NASA’s Swift and Rossi X-ray Timing Explorer (RXTE) satellites, astronomers have discovered one of the most bizarre planet-mass objects ever found. The object’s minimum mass is only about 7 times the mass of Jupiter. But instead of orbiting a normal star, this low-mass body orbits a rapidly (182 Hz) spinning pulsar. It orbits the pulsar every 54.7 minutes at an average distance of only about 230,000 miles (slightly less than the Earth-Moon distance). [ from the NASA press release ]
As part of a team led by Hans Krimm (Goddard), we analysed the RXTE observations following the discovery of this system, Swift J1756.9-2508. Hans' paper has now been accepted by ApJL and has been posted on arXiv.org. The story has shown up in a few places on the web, including the October 17 Monash Memo and even got a peripheral mention in a NY Times story
Read the paper (arXiv.org/0709.1693; ApJ 668, L147) or the
NASA press release
