Observation data Epoch J2000 Equinox J2000 | |
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Constellation | Cepheus |
Right ascension | 21 27 46.14144 |
Declination | +66° 48′ 32.7406″ |
Apparent magnitude (V) | 5.42 |
Characteristics | |
Evolutionary stage | main sequence |
Spectral type | B7 V |
B−V color index | −0.099±0.004 |
Astrometry | |
Radial velocity (Rv) | +3.0±4.2 km/s |
Proper motion (μ) | RA: −11.296 mas/yr Dec.: −19.787 mas/yr |
Parallax (π) | 3.9653 ± 0.1148 mas |
Distance | 820 ± 20 ly (252 ± 7 pc) |
Absolute magnitude (MV) | −1.54 |
Details | |
Mass | 4.47±0.07 M☉ |
Radius | 3.0 R☉ |
Luminosity | 769+94 −84 L☉ |
Surface gravity (log g) | 3.56 cgs |
Temperature | 12,560+87 −86 K |
Metallicity | −0.36 dex |
Rotational velocity (v sin i) | 236 km/s |
Age | 38 Myr |
Other designations | |
7 Cep, BD+66°1405, FK5 3718, HD 204770, HIP 105972, HR 8227, SAO 19432 | |
Database references | |
SIMBAD | data |
7 Cephei is a single star located approximately 820 light years away, in the northern circumpolar constellation of Cepheus. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.42.
This is a B-type main-sequence star with a stellar classification of B7 V. It is a candidate variable star with an amplitude of 9 micromagnitudes and a period of 0.737±0.002 d. This object has 4.5 times the mass of the Sun and about three times the Sun's radius. It is spinning rapidly with a projected rotational velocity of 236 km/s. 7 Cephei is radiating 769 times the luminosity of the Sun from its photosphere at an effective temperature of 12,560 K.
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ Zorec, J.; et al. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi:10.1086/190179
- Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 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.
- ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (2) (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ Niemczura, E. (June 2003), "Metallicities of the SPB stars from the IUE ultraviolet spectra", Astronomy and Astrophysics, 404 (2): 689–700, Bibcode:2003A&A...404..689N, doi:10.1051/0004-6361:20030546
- Gullikson, Kevin; et al. (2016), "The Close Companion Mass-Ratio Distribution of Intermediate-Mass Stars", The Astronomical Journal, 152 (2): 40, arXiv:1604.06456, Bibcode:2016AJ....152...40G, doi:10.3847/0004-6256/152/2/40, S2CID 119179065.
- "7 Cep". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 25, 2019.
- Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- Burggraaff, O.; et al. (September 2018), "Studying bright variable stars with the Multi-site All-Sky CAmeRA (MASCARA)", Astronomy & Astrophysics, 617: 11, arXiv:1806.02247, Bibcode:2018A&A...617A..32B, doi:10.1051/0004-6361/201833142, S2CID 84836583, A32.
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