Astronomy:SWIFT J1756.9−2508

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Short description: Millisecond pulsar in the constellation Sagittarius
SWIFT J1756.9−2508
Observation data
Equinox J2000.0]] (ICRS)
Constellation Sagittarius
Right ascension  17h 56m 57.200s
Declination −25° 06′ 26.28″
Astrometry
Distance8000 pc
Details
Mass1.8±0.4 M

SWIFT J1756.9−2508 is a millisecond pulsar with a rotation frequency of 182 Hz (period of 5.5 ms). It was discovered in 2007 by the Swift Gamma-Ray Burst Explorer and found to have a companion with a mass between 0.0067 and 0.030 solar masses. It is thought that the companion is the remnant of a former companion star, now stripped down to a planetary-mass core. The pulsar is accreting mass from this companion, resulting in occasional violent outbursts from the accumulated material on the neutron star.

Planetary system

SWIFT J1756.9-2508's only known planet is notable for its orbital period of less than an hour, about 54 minutes and 43 seconds.

The SWIFT J1756.9−2508 planetary system[1]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b (unconfirmed) 7.8 (± 1.3) MJ 0.0379907 (± 5e-07) d

References

  • H. A. Krimm; C. B. Markwardt; C. J. Deloye; P. Romano et al. (October 2007). "Discovery of the accretion-powered millisecond pulsar SWIFT J1756.9-2508 with a low-mass companion". Astrophysical Journal Letters 668 (2): L147–L150. doi:10.1086/522959. Bibcode2007ApJ...668L.147K. 
  • H. A. Krimm; C. B. Markwardt; C. J. Deloye; P. Romano et al. (October 2009). "ERRATUM: Discovery of the accretion-powered millisecond pulsar SWIFT J1756.9-2508 with a low-mass companion". Astrophysical Journal Letters 703 (2): L183. doi:10.1088/0004-637X/703/2/L183. Bibcode2009ApJ...703L.183K. 

External links