Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) |
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Constellation | Ara |
Right ascension | 16h 47m 10.20s |
Declination | -45° 52′ 16.8″ |
Characteristics | |
Evolutionary stage | Neutron star |
Apparent magnitude () | >18.5[1] |
Astrometry | |
Distance | approx. 16000 ly (approx. 5000 pc) |
Details | |
Rotation | 10.6105(1)s |
Other designations | |
CXO J164710.20-455217, CXO J164710.2-455217
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CXO J164710.2-455216 is an anomalous X-ray pulsar in the massive galactic open cluster Westerlund 1. It is the brightest X-ray source in the cluster, and was discovered in 2005 in observations made by the Chandra X-ray observatory.[2][1] The Westerlund 1 cluster is believed to have formed in a single burst of star formation,[3] implying that the progenitor star must have had a mass in excess of 40 solar masses. The fact that a neutron star was formed instead of a black hole implies that more than 95% of the star's original mass must have been lost before or during the supernova that produced the magnetar.
On 21st September 2006 the Swift satellite detected a 20ms soft Gamma-ray burst in Westerlund 1. Fortuitously, XMM-Newton observations had been made four days earlier, and repeat observations 1.5 days after the burst revealed the magnetar to be the source of the burst, with the X-ray luminosity increasing by a factor of 100 during the outburst.[4]