24 Capricorni

24 Capricorni
Location of α Capricorni (red circled)
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]
Distance460 ± 10 ly
(140 ± 4 pc)
Absolute magnitude (MV)−1.24[2]
Details
Radius54.06+1.88
−2.72[5] R☉
Luminosity611±41[5] L☉
Temperature3,903+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
SIMBADdata

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 name Tsoo, representing the state of Chu. 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

  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ Benjamin Apthorp Gould, URANOMETRIA ARGENTINA, archived from the original on 2012-02-27, retrieved 2019-06-10.
  7. ^ "24 Cap". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-06-15.
  8. ^ 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.
  9. ^ R.H.Allen, Star Names, p. 142, retrieved 2019-06-10.