V381 Cephei
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Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cepheus |
Right ascension | 21h 19m 15.68734s[1] |
Declination | +58° 37′ 24.6101″[1] |
Apparent magnitude (V) | 5.51 - 5.71[2] |
Characteristics | |
Spectral type | M1epIb + B[3] |
U−B color index | 0.00[4] |
B−V color index | +1.34[4] |
Variable type | Lc[2] |
Astrometry | |
Radial velocity (Rv) | −14.10[5] km/s |
Proper motion (μ) | RA: −3.90[1] mas/yr Dec.: −3.02[1] mas/yr |
Parallax (π) | 1.69 ± 0.53[1] mas |
Distance | approx. 1,900 ly (approx. 600 pc) |
Absolute magnitude (MV) | −5.2[6] |
Details | |
Aa | |
Mass | 7.2[7] - 16[8] M☉ |
Luminosity | 26,000[9] L☉ |
Temperature | 3,550[10] K |
Ab | |
Mass | 13[8] M☉ |
B | |
Mass | 11[8] M☉ |
Age | 49.1[7] Myr |
Other designations | |
A: HD 203338 | |
B: HD 203339 | |
Database references | |
SIMBAD | data |
V381 Cephei (HR 8164) is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7.
System
V381 Cephei is a visual double star with components A and B separated by 4.6". The primary is HD 203338 and the secondary is the magnitude 9.2 HD 203339.[8]
HD 203338 is itself a spectroscopic binary with components Aa and Ab orbiting every 280 years.[8] It forms a VV Cephei-type binary system with a hot companion which is accreting mass from the primary. The long period means that it exhibits fewer peculiarities than other VV Cephei binaries.[11]
Properties
Component Aa is a red supergiant and its close companion is a B2 main sequence star. The supergiant is a pulsating variable with a small amplitude and poorly defined period. It is generally given spectral class qualifiers indicating peculiarities and emission, which may be associated with the disc around the hot secondary.[11]
Component B, HD 203339, is a B3 main sequence star with a mass around 11 M☉.[8]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653. arXiv:0708.1752. Bibcode 2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ↑ 2.0 2.1 Samus, N. N.Expression error: Unrecognized word "etal". (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S 1. Bibcode 2009yCat....102025S.
- ↑ Josselin, E.; Plez, B. (2007). "Atmospheric dynamics and the mass loss process in red supergiant stars". Astronomy and Astrophysics 469 (2): 671. arXiv:0705.0266. Bibcode 2007A&A...469..671J. doi:10.1051/0004-6361:20066353.
- ↑ 4.0 4.1 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode 2002yCat.2237....0D.
- ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759. arXiv:1606.08053. Bibcode 2006AstL...32..759G. doi:10.1134/S1063773706110065.
- ↑ Stothers, R.; Leung, K. C. (1971). "Luminosities, masses and periodicities of massive red supergiants". Astronomy and Astrophysics 10: 290. Bibcode 1971A&A....10..290S.
- ↑ 7.0 7.1 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society 410: 190. arXiv:1007.4883. Bibcode 2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Tokovinin, A. A. (1997). "MSC - a catalogue of physical multiple stars". Astronomy and Astrophysics Supplement Series 124: 75. Bibcode 1997A&AS..124...75T. doi:10.1051/aas:1997181.
- ↑ Garmany, C. D.; Stencel, R. E. (1992). "Galactic OB associations in the northern Milky Way Galaxy. I - Longitudes 55 deg to 150 deg". Astronomy and Astrophysics Supplement Series 94: 211. Bibcode 1992A&AS...94..211G.
- ↑ Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten 331 (4): 349. arXiv:1003.2335. Bibcode 2010AN....331..349H. doi:10.1002/asna.200911355.
- ↑ 11.0 11.1 Halbedel, Elaine M. (1991). "Photometric variability for the VV Cephei-like star HR 8164". Astronomical Society of the Pacific 103: 310. Bibcode 1991PASP..103..310H. doi:10.1086/132820.