Astronomy:24 Cephei
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 09m 48.43066s[1] |
| Declination | +72° 20′ 28.3397″[1] |
| Apparent magnitude (V) | 4.79[2] |
| Characteristics | |
| Evolutionary stage | red giant branch[1] |
| 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: +33.041[1] mas/yr Dec.: +2.809[1] mas/yr |
| Parallax (π) | 8.2802 ± 0.0916[1] mas |
| Distance | 394 ± 4 ly (121 ± 1 pc) |
| Absolute magnitude (MV) | −0.519[4] |
| Details | |
| Mass | 3.50[5] M☉ |
| Radius | 16.8[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 |
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 8.28 mas,[1] is around 394 light years. It is moving closer with a heliocentric radial velocity of −17 km/s.[4]
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 times the mass of the Sun[5] and has expanded to about 17 times the Sun's radius.[6] The star is radiating 199 times the Sun's luminosity[2] from its enlarged photosphere at an effective temperature of 5,023 K.[7] These coordinates are a source of X-ray emission.[12]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 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, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ 4.0 4.1 4.2 4.3 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, doi:10.1051/0004-6361:20078788, Bibcode: 2008A&A...480...91S.
- ↑ 5.0 5.1 5.2 5.3 5.4 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, doi:10.1093/pasj/60.4.781, Bibcode: 2008PASJ...60..781T.
- ↑ 6.0 6.1 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel et al. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series 268 (1): 4. doi:10.3847/1538-4365/acdee5. Bibcode: 2023ApJS..268....4F.
- ↑ 7.0 7.1 7.2 7.3 Koleva, M.; Vazdekis, A. (February 2012), "Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library", Astronomy & Astrophysics 538: A143, doi:10.1051/0004-6361/201118065, Bibcode: 2012A&A...538A.143K.
- ↑ Lèbre, A. et al. (May 2006), "Lithium abundances and rotational behavior for bright giant stars", Astronomy and Astrophysics 450 (3): 1173–1179, doi:10.1051/0004-6361:20053485, Bibcode: 2006A&A...450.1173L.
- ↑ "24 Cep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=24+Cep.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Roman, Nancy G. (1952), "The Spectra of the Bright Stars of Types F5-K5", Astrophysical Journal 116: 122–143, doi:10.1086/145598, Bibcode: 1952ApJ...116..122R.
- ↑ 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, doi:10.1088/0067-0049/184/1/138, Bibcode: 2009ApJS..184..138H.
 |  |
