22 Vulpeculae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 15m 30.2386s[1] |
| Declination | +23° 30′ 32.051″[1] |
| Apparent magnitude (V) | 5.176[2] |
| Characteristics | |
| Spectral type | G2II + B8.5V[3] |
| U−B color index | +1.03[4] |
| B−V color index | +0.68[4] |
| Variable type | Algol |
| Astrometry | |
| Radial velocity (Rv) | −22.8±0.9[5] km/s |
| Proper motion (μ) | RA: 2.852±0.067[1] mas/yr Dec.: −7.278±0.071[1] mas/yr |
| Parallax (π) | 2.1872 ± 0.0850 mas[1] |
| Distance | 1,490 ± 60 ly (460 ± 20 pc) |
| Absolute magnitude (MV) | −3.67[6] (−3.5 / −0.1)[7] |
| Orbit[8] | |
| Period (P) | 249.1310±0.0060 d |
| Eccentricity (e) | 0 (assumed) |
| Argument of periastron (ω) (secondary) | 0 (assumed)° |
| Semi-amplitude (K1) (primary) | 27.03±0.14 km/s |
| Details[7] | |
| 22 Vul A | |
| Mass | 5.4 M☉ |
| Radius | 77 R☉ |
| Temperature | 4700 K |
| 22 Vul B | |
| Mass | 3.4 M☉ |
| Radius | 3.3 R☉ |
| Temperature | 10900 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
22 Vulpeculae is a binary star[3] system in the northern constellation Vulpecula. Based on its parallax, it is located some 1,490 light-years away,[1] and it has an apparent magnitude of about 5.176,[2] making it visible to the naked eye. The system is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.[5]
The pair have an orbital period of 0.68 yr in what is assumed to be a circular orbit.[8] The primary component is a G-type bright giant. It is over five times as massive as the Sun, and over 77 times as wide. Its companion is a B-type main-sequence star, 3.4 times as massive as the Sun.[7] The stars have an orbit that are oriented in such a way that they periodically eclipse each other, blocking the other star's light. For that, it has been given the variable star designation QS Vulpeculae;[9] 22 Vulpeculae is the Flamsteed designation.
References
- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- ^ a b Weaver, Wm. Bruce (2000). "Spectral Classification of Unresolved Binary Stars with Artificial Neural Networks". The Astrophysical Journal. 541 (1): 298–305. Bibcode:2000ApJ...541..298W. doi:10.1086/309425.
- ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ a b Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington. Bibcode:1953GCRV..C......0W.
- ^ Gray, David F.; Pugh, Teznie (2012). "The Third Signature of Granulation in Bright-Giant and Supergiant Stars". The Astronomical Journal. 143 (4): 92. Bibcode:2012AJ....143...92G. doi:10.1088/0004-6256/143/4/92.
- ^ a b c Schroeder, K.-P.; Griffin, R. E. M.; Hunsch, M. (1994). "Optical spectra of zeta Aurigae binary systems. 6: The chromosphere of 22 Vulpeculae". Astronomy and Astrophysics. 288 (1): 273–281. Bibcode:1994A&A...288..273S.
- ^ a b Griffin, R. E. M.; et al. (July 1993). "Optical spectra of dzeta Aurigae binary systems. V. The 1988 eclipse of 22 Vulpeculae". Astronomy and Astrophysics. 274: 225. Bibcode:1993A&A...274..225G.
- ^ a b "* 22 Vul". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 13 May 2017.
