20 Vulpeculae is single[5] star located around 1,170[1] light years away in the northern constellation of Vulpecula.[8] It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.91.[2] The object is moving closer to the Earth with a heliocentric radial velocity of −22 km/s.[2]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Vulpecula |
Right ascension | 20h 12m 00.70176s[1] |
Declination | +26° 28′ 43.6989″[1] |
Apparent magnitude (V) | 5.91[2] |
Characteristics | |
Evolutionary stage | main sequence[3] |
Spectral type | B7 Ve[4][5] |
B−V color index | −0.107±0.003[2] |
Astrometry | |
Radial velocity (Rv) | −22.0±4.3[2] km/s |
Proper motion (μ) | RA: +4.096[1] mas/yr Dec.: −9.524[1] mas/yr |
Parallax (π) | 2.7904 ± 0.0726 mas[1] |
Distance | 1,170 ± 30 ly (358 ± 9 pc) |
Absolute magnitude (MV) | −2.13[2] |
Details | |
Mass | 4.02±0.14[3] M☉ |
Radius | 3.0[6] R☉ |
Luminosity | 460+88 −74[3] L☉ |
Surface gravity (log g) | 2.90[7] cgs |
Temperature | 12,050+168 −165[3] K |
Rotational velocity (v sin i) | 236[3] km/s |
Other designations | |
Database references | |
SIMBAD | data |
This is a Be star with a stellar classification of B7 Ve.[4] It is spinning rapidly with a projected rotational velocity of 236 km/s (compared to a critical velocity of 332 km/s)[3] and has an estimated polar inclination of 71.1°.[9] The star has four times the mass of the Sun and is radiating around 460 times the Sun's luminosity from its photosphere at an effective temperature of 12,050 K.[3]