12 Vulpeculae
Star in the constellation Vulpecula
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12 Vulpeculae is a star in the northern constellation of Vulpecula, located approximately 630 light years away based on parallax. It has the variable star designation V395 Vul; 12 Vulpeculae is the Flamsteed designation. This object is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of about 4.9. It is moving closer to the Earth with a heliocentric radial velocity of -25 km/s.
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vulpecula[1] |
| Right ascension | 19h 51m 04.1083s[2] |
| Declination | +22° 36′ 36.173″[2] |
| Apparent magnitude (V) | 4.78 - 4.97[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | B2.5V[1] |
| Apparent magnitude (U) | 4.104±0.020[4] |
| Apparent magnitude (B) | 4.759±0.017[4] |
| Variable type | Be star[3] |
| Astrometry | |
| Radial velocity (Rv) | −24.90[5] km/s |
| Proper motion (μ) | RA: 23.404±0.068[2] mas/yr Dec.: −15.797±0.099[2] mas/yr |
| Parallax (π) | 5.1710±0.1070 mas[2] |
| Distance | 630 ± 10 ly (193 ± 4 pc) |
| Absolute magnitude (MV) | −1.52[1] |
| Details | |
| Mass | 6.8[6] M☉ |
| Luminosity | 963[1] L☉ |
| Surface gravity (log g) | 3.36[7] cgs |
| Temperature | 18,859[7] K |
| Metallicity [Fe/H] | −0.01[7] dex |
| Rotational velocity (v sin i) | 195[8] km/s |
| Other designations | |
| 12 Vul, V395 Vul, BD+22°3833, FK5 3585, GC 27493, HD 187811, HIP 97679, HR 7565, SAO 87813[9] | |
| Database references | |
| SIMBAD | data |
This is a variable Be star with a stellar classification of B2.5V;[1] its brightness ranges from magnitude 4.78 down to 4.97.[3] As is true with other Be stars, it has a high rate of rotation with a projected rotational velocity of 195 km/s.[8] The star has 6.8[6] times the mass of the Sun and is radiating 963[1] times the Sun's luminosity from its photosphere at an effective temperature of 18,859 K.[7]