V381 Cephei

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V381 Cephei
Cepheus constellation map.svg
Red circle.svg
Location of V381 Cephei (circled)
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]
Spectral type M1epIb + B[3]
U−B color index 0.00[4]
B−V color index +1.34[4]
Variable type Lc[2]
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
Distanceapprox. 1,900 ly
(approx. 600 pc)
Absolute magnitude (MV)−5.2[6]
Mass7.2[7] - 16[8] M
Luminosity26,000[9] L
Temperature3,550[10] K
Mass13[8] M
Mass11[8] M
Age49.1[7] Myr
Other designations
V381 Cephei, HR 8164, HIP 105259, BD+58°2249, ADS 14864, 2MASS J21191567+5837246, WDS J21193+5837
A: HD 203338
B: HD 203339
Database references

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.


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]


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]


  1. 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. 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.
  3. 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. 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.
  5. 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.
  6. 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. 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. 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.
  9. 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.
  10. 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. 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.