24 Cephei is a single,[10] yellow-hued star in the northern circumpolar constellation of Cepheus. With an apparent visual magnitude of 4.79,[2] it is faintly visible to the naked eye. The distance to this star, based upon an annual parallax shift of 8.3965 mas,[1] is around 388 light years. It is moving closer with a heliocentric radial velocity of −17 km/s.[4]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 09m 48.43010s[1] |
| Declination | +72° 20′ 28.3421″[1] |
| Apparent magnitude (V) | 4.79[2] |
| Characteristics | |
| Spectral type | G7 II-III[3] |
| B−V color index | 0.898[4] |
| Astrometry | |
| Radial velocity (Rv) | −16.58[4] km/s |
| Proper motion (μ) | RA: +33.214[1] mas/yr Dec.: +2.679[1] mas/yr |
| Parallax (π) | 8.3965 ± 0.1332 mas[1] |
| Distance | 388 ± 6 ly (119 ± 2 pc) |
| Absolute magnitude (MV) | −0.519[4] |
| Details | |
| Mass | 3.50[5] M☉ |
| Radius | 13[6] R☉ |
| Luminosity | 209[5] L☉ |
| Surface gravity (log g) | 2.31±0.33[7] cgs |
| Temperature | 5,023±54[7] K |
| Metallicity [Fe/H] | −0.16±0.11[7] dex |
| Rotational velocity (v sin i) | 6.5[8] km/s |
| Age | 234[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Keenan and McNeil (1989) listed a stellar classification of G7 II-III[3] for 24 Cep, matching the spectrum of an evolved G-type star with blended features of a bright giant and a giant star. Older sources list a class of G8 III,[11] which would suggest an ordinary giant star. At the age of 234 million years,[5] it has an estimated 3.5[5] times the mass of the Sun and has expanded to about 13[6] times the Sun's radius. The star is radiating 199[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,023 K.[7] These coordinates are a source of X-ray emission.[12]
References
edit- ^ a b c d e f 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.
- ^ a b c 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.
- ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", The Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ^ a b c d Soubiran, C.; et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics, 480 (1): 91–101, arXiv:0712.1370, Bibcode:2008A&A...480...91S, doi:10.1051/0004-6361:20078788, S2CID 16602121.
- ^ a b c d e Takeda, Yoichi; et al. (August 2008), "Stellar parameters and elemental abundances of late-G giants", Publications of the Astronomical Society of Japan, 60 (4): 781–802, arXiv:0805.2434, Bibcode:2008PASJ...60..781T, doi:10.1093/pasj/60.4.781.
- ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ a b c d Koleva, M.; Vazdekis, A. (February 2012), "Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library", Astronomy & Astrophysics, 538: A143, arXiv:1111.5449, Bibcode:2012A&A...538A.143K, doi:10.1051/0004-6361/201118065, S2CID 53999614.
- ^ Lèbre, A.; et al. (May 2006), "Lithium abundances and rotational behavior for bright giant stars", Astronomy and Astrophysics, 450 (3): 1173–1179, Bibcode:2006A&A...450.1173L, doi:10.1051/0004-6361:20053485.
- ^ "24 Cep". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-06.
- ^ 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.
- ^ Roman, Nancy G. (1952), "The Spectra of the Bright Stars of Types F5-K5", Astrophysical Journal, 116: 122–143, Bibcode:1952ApJ...116..122R, doi:10.1086/145598.
- ^ Haakonsen, Christian Bernt; Rutledge, Robert E. (September 2009), "XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources", The Astrophysical Journal Supplement, 184 (1): 138–151, arXiv:0910.3229, Bibcode:2009ApJS..184..138H, doi:10.1088/0067-0049/184/1/138, S2CID 119267456.