Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Vulpecula |
2 Vul A | |
Right ascension | 19h 17m 43.6354s[1] |
Declination | +23° 01′ 31.9418″[1] |
Apparent magnitude (V) | 5.43[2] |
2 Vul B | |
Right ascension | 19h 17m 43.7343s[3] |
Declination | +23° 01′ 30.8604″[3] |
Characteristics | |
Spectral type | B1 IV[4] |
B−V color index | 0.020±0.003[2] |
Variable type | β Cep[5] |
Astrometry | |
2 Vul A | |
Radial velocity (Rv) | +1.0±4.2[2] km/s |
Proper motion (μ) | RA: +0.956±0.041[1] mas/yr Dec.: −6.636±0.087[1] mas/yr |
Parallax (π) | 1.8212 ± 0.0880 mas[1] |
Distance | 1,790 ± 90 ly (550 ± 30 pc) |
Absolute magnitude (MV) | −2.35[2] |
2 Vul B | |
Proper motion (μ) | RA: −0.170±0.038[3] mas/yr Dec.: −5.324±0.073[3] mas/yr |
Parallax (π) | 1.7131 ± 0.0757 mas[3] |
Distance | 1,900 ± 80 ly (580 ± 30 pc) |
Details | |
Mass | 12.5±0.6[6] M☉ |
Luminosity (bolometric) | 21,922[7] L☉ |
Temperature | 26,850[7] K |
Metallicity [Fe/H] | −0.06±0.10[8] dex |
Rotational velocity (v sin i) | 270[9] km/s |
Age | 12.6±0.7[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
2 Vulpeculae is a binary star[11] system in the northern constellation of Vulpecula, located around 1,800 light years away[1] from the Sun. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 5.43.[2]
2 Vulpeculae is a double-lined spectroscopic binary;[11] as of 2002, the pair had an angular separation of 1.72″ along a position angle of 127.2°.[12]
The primary component of the binary is a rapidly rotating Be star[13] with a stellar classification of B1 IV.[4] It is a variable star with an amplitude of 0.06 magnitude and a period of 0.6096 days, tentatively classified as Beta Cephei variable.[5] The variability was discovered in 1959,[14] and it has been assigned the variable star designation ES Vulpeculae.[5]