CXOU J164710.2−455216

Anomalous X-ray pulsar in Westerlund 1

CXOU J164710.2−455216
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Artist's impression of CXOU J164710.2-455216
Constellation	Ara
Right ascension	16^h 47^m 10.20^s
Declination	−45° 52′ 16.8″
Characteristics
Evolutionary stage	Neutron star
Apparent magnitude ( ${\begin{smallmatrix}K_{s}\end{smallmatrix}}$ )	>18.5^[1]
Astrometry

Distance	approx. 16,000 ly (approx. 5,000 pc)

Details

Rotation	10.6105(1)s

Other designations
CXO J164710.20−455217, CXOU J164710.2−455217
Database references
SIMBAD	data

CXOU J164710.2−455216 is an anomalous X-ray pulsar and magnetar 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.^[1]^[2] 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.^[4]^[5]

On 21 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.^[6]

References

^ ^a ^b A Neutron Star with a Massive Progenitor in Westerlund 1, Muno et al. (2006)
^ Westerlund 1: Neutron Star Discovered Where a Black Hole Was Expected
^ On the massive stellar population of the super star cluster Westerlund 1, Clark et al. (2005)
^ Magnetar Formation Mystery Solved, eso1415 - Science Release (14 May 2014)
^ Wood, Chris. "Very Large Telescope solves magnetar mystery" GizMag, 14 May 2014. Accessed: 18 May 2014.
^ Exciting the magnetosphere of the magnetar CXOU J164710.2−455216 in Westerlund 1, Muno et al. (2007)

Gavriil, F. P.; Woods, P. M.; Kaspi, V. M. (2006). "Chandra Target of Opportunity Observations of CXO J164710.2−455216". The Astronomer's Telegram. 901: 1. Bibcode:2006ATel..901....1G.
cxo-j164710.2-455216

Constellation of Ara

Stars

Bayer	α (Choo/Tchou) β γ δ ε¹ ε² ζ (Tseen Yin) η θ ι κ λ μ (Cervantes) ν¹ (V539) ν² π ρ¹ ρ² σ
Variable	R S OY V626 V821 V828 V829 V854 V862 V872
HR	6177 6187 6207 6236 6251 6253 6297 6300 6312 6323 6408 6416 (41 G.) 6423 6438 6477 6478 6483 6487 6513 6759
HD	152079 153201 154672 154857 156411 (Inquill)
Other	2MASS J18082002−5104378 CXOU J164710.2−455216 Gliese 674 Gliese 676 IRAS 16594-4656 SAO 244567 SGR 1627−41 Westerlund 1-20 Westerlund 1 W26 Westerlund 1-75 Westerlund 1-237 Westerlund 1-243 XTE J1650−500