Black Widow pulsar
The blue and green are optical images of the field in which the Black Widow pulsar is found, the green indicating the H-alpha bow shock. The red and white are the colors of the shock structures discovered in x-ray by the Chandra X-ray Observatory. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagitta |
| Right ascension | 19h 59m 36.764s |
| Declination | +20° 48′ 14.90″ |
| Apparent magnitude (V) | 20.16 – 26.2 |
| Astrometry | |
| Proper motion (μ) | RA: −19.267 mas/yr Dec.: −26.560 mas/yr |
| Parallax (π) | 1.1878±1.3556 mas |
| Distance | 6,500 ly (2,000 pc) |
| Details | |
| Pulsar | |
| Mass | 2.4 M☉ |
| Rotation | 1.60740168480632 ms |
| Companion | |
| Mass | 0.035 M☉ |
| Other designations | |
| QX Sge, PSR J1959+2048, PSR B1957+20 | |
| Database references | |
| SIMBAD | data |
The Black Widow pulsar (PSR B1957+20) is an eclipsing binary millisecond pulsar in the Milky Way. Discovered in 1988, it is located roughly 6,500 light-years (2,000 parsecs) away from Earth. It completes rotation period of 1.6074 milliseconds. It orbits with a brown dwarf or super-Jupiter companion with a period of 9.2 hours with an eclipse duration of approximately 20 minutes. When it was discovered, it was the first such pulsar known.