12 Vulpeculae is a star in the northern constellation of Vulpecula, located approximately 630 light years away based on parallax.[1] 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 a baseline apparent visual magnitude of 4.928.[2] It is moving closer to the Earth with a heliocentric radial velocity of -25 km/s.[5]

12 Vulpeculae

Location of 12 Vulpeculae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Vulpecula
Right ascension	19h 51m 04.1083s[1]
Declination	+22° 36′ 36.173″[1]
Apparent magnitude (V)	4.928±0.015[2] (4.78 - 4.97)[3]
Characteristics
Spectral type	B2.5V[4]
Apparent magnitude (U)	4.104±0.020[2]
Apparent magnitude (B)	4.759±0.017[2]
Variable type	Be star[3]
Astrometry
Radial velocity (Rv)	−24.90[5] km/s
Proper motion (μ)	RA: 23.404±0.068[1] mas/yr Dec.: −15.797±0.099[1] mas/yr
Parallax (π)	5.1710 ± 0.1070 mas[1]
Distance	630 ± 10 ly (193 ± 4 pc)
Absolute magnitude (MV)	−1.52[4]
Details
Mass	6.8[6] M☉
Luminosity	963[4] 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;[4] 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[4] times the Sun's luminosity from its photosphere at an effective temperature of 18,859 K.[7]

References