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19 Cephei 
Summary
19 Cephei is a supergiant star in the northern circumpolar constellation of Cepheus. It has a spectral class of O9 and is a member of Cep OB2, an OB association of massive stars located about 615 parsecs (2,010 ly) from the Sun.
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 05m 08.78995s[1] |
| Declination | +62° 16′ 47.3301″[1] |
| Apparent magnitude (V) | 5.08[2] |
| Characteristics | |
| Spectral type | O9Ib[3] |
| U−B color index | −0.91[2] |
| B−V color index | +0.06[2] |
| Astrometry | |
| Radial velocity (Rv) | −12.8±0.9[4] km/s |
| Proper motion (μ) | RA: −1.16[1] mas/yr Dec.: −2.96[1] mas/yr |
| Parallax (π) | 1.58 ± 0.19 mas[1] |
| Distance | 1,200[5] pc |
| Absolute magnitude (MV) | −5.45[6] |
| Details | |
| Mass | 20[7] M☉ |
| Radius | 17.0[3] R☉ |
| Luminosity | 224,000[3] L☉ |
| Surface gravity (log g) | 3.40±0.08[8] cgs |
| Temperature | 32,983±1,428[8] K |
| Metallicity [Fe/H] | 0.06±0.08[8] dex |
| Rotational velocity (v sin i) | 48[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of 19 Cephei shows line profile variability on an hourly and daily timescale. This is thought to be due to the changes in the stellar wind.[3]
Double star catalogues list several companions for 19 Cephei. The Washington Double Star Catalog describes four companions: 11th magnitude stars 20" and 56" away, and two 15th magnitude stars 4-5" away.[9] The Catalog of Components of Double and Multiple Stars gives only the two 11th magnitude stars.[10]
A scattered cluster of faint stars has been detected associated with 19 Cephei. The brightest likely members apart from 19 Cep itself are 10th magnitude stars.[11]
References edit
- ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600Vizier catalog entry
- ^ a b c Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M
- ^ a b c d e Martins, F.; Marcolino, W.; Hillier, D. J.; Donati, J.-F.; Bouret, J.-C. (2015). "Radial dependence of line profile variability in seven O9-B0.5 stars". Astronomy & Astrophysics. 574: A142. arXiv:1409.5057. Bibcode:2015A&A...574A.142M. doi:10.1051/0004-6361/201423882. S2CID 118365203.
- ^ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ Aldoretta, E. J.; Caballero-Nieves, S. M.; Gies, D. R.; Nelan, E. P.; Wallace, D. J.; Hartkopf, W. I.; Henry, T. J.; Jao, W.-C.; Maíz Apellániz, J.; Mason, B. D.; Moffat, A. F. J.; Norris, R. P.; Richardson, N. D.; Williams, S. J. (2015). "The Multiplicity of Massive Stars: A High Angular Resolution Survey with the Guidance Sensor". The Astronomical Journal. 149 (1): 26. arXiv:1410.0021. Bibcode:2015AJ....149...26A. doi:10.1088/0004-6256/149/1/26. S2CID 58911264.
- ^ Puls, J.; Markova, N.; Scuderi, S.; Stanghellini, C.; Taranova, O. G.; Burnley, A. W.; Howarth, I. D. (2006). "Bright OB stars in the Galaxy. III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Hα, IR and radio analysis". Astronomy and Astrophysics. 454 (2): 625. arXiv:astro-ph/0604372. Bibcode:2006A&A...454..625P. doi:10.1051/0004-6361:20065073. S2CID 18271791.
- ^ Villamariz, M. R.; et al. (June 2002), "Chemical composition of Galactic OB stars I. CNO abundances in O9 stars", Astronomy and Astrophysics, 388 (3): 940–956, arXiv:astro-ph/0204209, Bibcode:2002A&A...388..940V, doi:10.1051/0004-6361:20020400, S2CID 1607478
- ^ a b c Prugniel, P.; Vauglin, I.; Koleva, M. (2011). "The atmospheric parameters and spectral interpolator for the MILES stars". Astronomy & Astrophysics. 531: A165. arXiv:1104.4952. Bibcode:2011A&A...531A.165P. doi:10.1051/0004-6361/201116769. S2CID 54940439.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
- ^ Dommanget, J.; Nys, O. (1994). "Catalogue des composantes d'etoiles doubles et multiples (CCDM) premiere edition - Catalogue of the components of double and multiple stars (CCDM) first edition". Com. De l'Observ. Royal de Belgique. 115: 1. Bibcode:1994CoORB.115....1D.
- ^ Kharchenko, N. V.; Piskunov, A. E.; Röser, S.; Schilbach, E.; Scholz, R.-D. (2005). "109 new Galactic open clusters". Astronomy and Astrophysics. 440 (1): 403–408. arXiv:astro-ph/0505019. Bibcode:2005A&A...440..403K. doi:10.1051/0004-6361:20052740. S2CID 56292154.
External links edit
- "* 19 Cep". SIMBAD. Centre de données astronomiques de Strasbourg.