V381 Cephei
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 21h 19m 15.682s |
| Declination | +58° 37′ 24.550″ |
| Apparent magnitude (V) | 5.51 - 5.71 |
| Characteristics | |
| Spectral type | M1epIb + B |
| U−B color index | 0.00 |
| B−V color index | +1.34 |
| Variable type | Lc |
| Astrometry | |
| Radial velocity (Rv) | −14.10 km/s |
| Proper motion (μ) | RA: −1.435 mas/yr Dec.: −5.427 mas/yr |
| Parallax (π) | 1.59±0.23 mas |
| Distance | approx. 2,100 ly (approx. 630 pc) |
| Absolute magnitude (MV) | −5.2 |
| Details | |
| Aa | |
| Mass | 7.2 - 16 M☉ |
| Radius | 977 R☉ |
| Luminosity | 178,000 L☉ |
| Temperature | 3,745±170 K |
| Ab | |
| Mass | 13 M☉ |
| B | |
| Mass | 7.1 M☉ |
| Radius | 3.4 R☉ |
| Luminosity | 1,487 L☉ |
| Surface gravity (log g) | 4.18 cgs |
| Temperature | 19,965 K |
| Metallicity [Fe/H] | −0.30 dex |
| Rotational velocity (v sin i) | 42.8 km/s |
| Age | 49.1 Myr |
| Other designations | |
| V381 Cephei, HR 8164, HIP 105259, BD+58°2249, ADS 14864, 2MASS J21191567+5837246, WDS J21193+5837 | |
| A: HD 203338 | |
| B: HD 203339 | |
| Database references | |
| A | |
| B | |
V381 Cephei (HR 8164) is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7. It is faintly visible to the naked eye under good observing conditions.
The star was discovered to be a variable star in 1991, by Elaine M. Halbedel. It was given its variable star designation, V381 Cephei, in 1995.