PSR B1257+12
PSR B1257+12, previously designated PSR 1257+12, alternatively designated PSR J1300+1240, is a millisecond pulsar located 2,300 light-years (710 parsecs) from the Sun in the constellation of Virgo, rotating at about 161 times per second (faster than a blender's blade). It is also named Lich, after a powerful, fictional undead creature of the same name.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 13h 00m 01s |
| Declination | +12° 40′ 57″ |
| Characteristics | |
| Spectral type | Pulsar |
| Astrometry | |
| Proper motion (μ) | RA: 46.44±0.08 mas/yr Dec.: −84.87±0.32 mas/yr |
| Parallax (π) | 1.41 ± 0.08 mas |
| Distance | 2,300 ± 100 ly (710 ± 40 pc) |
| Details | |
| Mass | 1.4 M☉ |
| Radius | ~0.000015 R☉ |
| Temperature | 28,856 K |
| Rotation | 0.006219 s |
| Age | 1–3 Gyr |
| Other designations | |
Lich, PSR 1257+12, PSR J1300+1240, PSR 1300+1240 | |
| Database references | |
| SIMBAD | data |
The pulsar has a planetary system with three known pulsar planets, named "Draugr" (PSR B1257+12 b or PSR B1257+12 A), "Poltergeist" (PSR B1257+12 c, or PSR B1257+12 B), and "Phobetor" (PSR B1257+12 d, or PSR B1257+12 C), respectively. They were both the first extrasolar planets and the first pulsar planets to be discovered; B and C in 1992 and A in 1994. A is the lowest-mass planet yet discovered by any observational technique, with somewhat less than twice the mass of Earth's moon.