V381 Cephei
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cepheus |
| V381 Cephei A | |
| Right ascension | 21h 19m 15.6852s |
| Declination | +58° 37′ 24.624″ |
| Apparent magnitude (V) | 5.51 - 5.71 |
| V381 Cephei B | |
| Right ascension | 21h 19m 16.1020s |
| Declination | +58° 37′ 27.844″ |
| Apparent magnitude (V) | 9.23 |
| Characteristics | |
| Spectral type | M1epIb + B |
| U−B color index | 0.00 |
| B−V color index | +1.34 |
| Variable type | Lc |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −14.10 km/s |
| Proper motion (μ) | RA: −1.893 mas/yr Dec.: −4.751 mas/yr |
| Parallax (π) | 0.5546±0.1793 mas |
| Distance | approx. 6,000 ly (approx. 1,800 pc) |
| Absolute magnitude (MV) | −5.2 |
| B | |
| Proper motion (μ) | RA: −2.490±0.025 mas/yr Dec.: −3.704±0.031 mas/yr |
| Parallax (π) | 1.1735±0.0171 mas |
| Distance | 2,780 ± 40 ly (850 ± 10 pc) |
| 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.