31 Persei
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Perseus |
| Right ascension | 03h 19m 07.63796s |
| Declination | 50° 05′ 41.8724″ |
| Apparent magnitude (V) | 5.05 |
| Characteristics | |
| Spectral type | B5V |
| U−B color index | −0.53 |
| B−V color index | −0.06 |
| Astrometry | |
| Radial velocity (Rv) | −1.60 km/s |
| Proper motion (μ) | RA: +23.580 mas/yr Dec.: −23.322 mas/yr |
| Parallax (π) | 5.8399±0.1792 mas |
| Distance | 560 ± 20 ly (171 ± 5 pc) |
| Absolute magnitude (MV) | −1.44 |
| Details | |
| Mass | 4.647 M☉ |
| Radius | 3.4 R☉ |
| Luminosity | 950 L☉ |
| Temperature | 15,301 K |
| Metallicity [Fe/H] | 0.00 dex |
| Rotational velocity (v sin i) | 260 km/s |
| Age | 234 Myr |
| Other designations | |
| 31 Per, BD+49°902, GC 3945, HD 20418, HIP 15444, HR 989, SAO 38714 | |
| Database references | |
| SIMBAD | data |
31 Persei is a single star in the northern constellation of Perseus. It is visible to the naked eye as a dim, blue-white hued point of light with an apparent visual magnitude of 5.05. This star is located around 172 parsecs (560 ly) away from the Sun, and it is drifting closer with a radial velocity of −1.6 km/s. It is likely a member of the Alpha Persei Cluster.
This object is a massive B-type main-sequence star with a stellar classification of B5V and it is currently generating energy through hydrogen fusion at its core. It is around 234 million years old and is spinning rapidly with a projected rotational velocity of 260 km/s. The star has 4.6 times the mass of the Sun and about 3.4 times the radius of the Sun. It is radiating 950 times the luminosity of the Sun from its photosphere at an effective temperature of 15,301 K.