PSR B1259−63

PSR B1259−63 is a pulsar and member of an eclipsing binary star system with the blue O9.5Ve-class star SS 2883. The pair has an eccentric orbit that is inclined to the line of sight from Earth by about 36°, leading to a 40-day-long eclipse each time the pulsar passes behind the star.^[5] The pulsar has a period of 47.762 milliseconds (ms) and a luminosity of 8.3 × 10³⁵ erg/s. It emits very high energy gamma rays that vary on a time scale of several days.^[10]

PSR B1259−63

The location of PSR J1302−6350 (circled in red)
Observation data Epoch J2000      Equinox J2000
Constellation	Centaurus[1]
Right ascension	13h 02m 47.654s[2]
Declination	−63° 50′ 08.63″[2]
Apparent magnitude (V)	9.98[3]
Characteristics
Evolutionary stage	Pulsar + Main sequence[4]
Spectral type	O9.5Ve[4]
Astrometry
Proper motion (μ)	RA: −7.093[2] mas/yr Dec.: −0.342[2] mas/yr
Parallax (π)	0.4434±0.0133 mas[2]
Distance	7,400 ± 200 ly (2,260 ± 70 pc)
Orbit[5]
Companion	SS 2883
Period (P)	3.389 years (1,237 days)
Eccentricity (e)	0.87
Inclination (i)	36°
Details
Pulsar
Rotation	47.7625075 ms
Age	332,000 years
O-type star
Mass	22.5[6] M☉
Radius	10.4[2] R☉
Luminosity	160,000[7] L☉
Surface gravity (log g)	3.84[8] cgs
Temperature	35,610[8] K
Rotational velocity (v sin i)	280 km/s
Other designations
AAVSO 1256−63, ALS 2883, AX J1302−638, CPD-63° 2495, GSC 08997-01597, Hbg 757, Hen 3-852, INTREF 538, LS 2883, MSX6C G304.1845-00.9916, PSR B1259−63 PSR J1302−6350, THA 17-8, TYC 8997-1597-1, UCAC2 3710789, WRAY 15-1053[9]
Database references
SIMBAD	data

The star SS 2883 has about 22.5 solar masses and is 10.4 solar radii in size. The rate of rotation is about 280 km/s at the equator, or 70% of the breakup velocity.^[5]