24 Capricorni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 21h 07m 07.66733s[1] |
| Declination | −25° 00′ 21.0790″[1] |
| Apparent magnitude (V) | +4.49[2] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | M1− III[4] |
| B−V color index | 1.604±0.005[2] |
| Astrometry | |
| Radial velocity (Rv) | +32.1±0.8[2] km/s |
| Proper motion (μ) | RA: −28.09[1] mas/yr Dec.: −44.14[1] mas/yr |
| Parallax (π) | 7.15±0.22 mas[1] |
| Distance | 460 ± 10 ly (140 ± 4 pc) |
| Absolute magnitude (MV) | −1.24[2] |
| Details | |
| Radius | 54.06+1.88 −2.72[5] R☉ |
| Luminosity | 611±41[5] L☉ |
| Temperature | 3,903+102 −66[5] K |
| Other designations | |
| A Capricorni[6], 24 Cap, CD−25°15235, FK5 791, GC 29490, HD 200914, HIP 104234, HR 8080, SAO 190025, ADS 14632, CCDM J21071-2500[7] | |
| Database references | |
| SIMBAD | data |
24 Capricorni or A Capricorni is a single[8] star in the southern constellation of Capricornus. This object is visible to the naked eye as a faint, red-hued star with an apparent visual magnitude of +4.49.[2] It is approximately 460 light years from the Sun, based on parallax.[1] The star is moving further from the Earth with a heliocentric radial velocity of +32 km/s.[2]
This is an aging red giant, currently on the asymptotic giant branch,[3] with a stellar classification of M1− III;[4] a star that has exhausted the supply of hydrogen at its core and expanded to 54[5] times the Sun's radius. It is radiating 611[5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,903 K.[5]
Chinese name
In R. H. Allen's book, this star is described as having the Chinese name Tsoo, representing the state of Chu,[9] though other sources identify φ Capricorni as Chu.[10] Bayer described it as one of the last three stars of the tail of the goat, although this is not how they appear in modern visual representations of the constellation.[9]
References
- ^ a b c d e f 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 18759600.
- ^ a b c d e f 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 Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal, 104 (1): 275–313, Bibcode:1992AJ....104..275E, doi:10.1086/116239.
- ^ a b Keenan, P. C.; McNeil, R. 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 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. Gaia DR2 record for this source at VizieR.
- ^ Benjamin Apthorp Gould, URANOMETRIA ARGENTINA, archived from the original on 2012-02-27, retrieved 2019-06-10.
- ^ "24 Cap". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-06-15.
- ^ 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.
- ^ a b R.H.Allen, Star Names, p. 142, retrieved 2019-06-10.
- ^ Ridpath, Ian. "Star Tales − Capricornus". Retrieved 7 December 2025.