36 Capricorni

This article is about b Capricorni. Not to be confused with β Capricorni.

36 Capricorni is a single,^[8] yellow-hued star in the southern constellation of Capricornus. It is visible to the naked eye with an apparent visual magnitude of +4.50.^[2] The distance to this star, as determined from an annual parallax shift of 19.06±0.29 mas,^[1] is around 171 light years. It is currently moving closer with a heliocentric radial velocity of −21 km/s, and will come within 145 ly (44.58 pc) in about 685,000 years ago.^[4]

36 Capricorni

Observation data Epoch J2000      Equinox J2000
Constellation	Capricornus
Right ascension	21h 28m 43.40070s[1]
Declination	−21° 48′ 25.8504″[1]
Apparent magnitude (V)	+4.50[2]
Characteristics
Spectral type	G7IIIb Fe–1[3]
B−V color index	0.889[1]
Astrometry
Radial velocity (Rv)	−20.8±0.9[4] km/s
Proper motion (μ)	RA: +134.83 mas/yr[1] Dec.: −5.73 mas/yr[1]
Parallax (π)	19.06 ± 0.29 mas[1]
Distance	171 ± 3 ly (52.5 ± 0.8 pc)
Absolute magnitude (MV)	0.811[5]
Details[6]
Mass	2.26±0.19 M☉
Radius	8.59±0.07 R☉
Luminosity	43.15±0.69 L☉
Surface gravity (log g)	2.96±0.10 cgs
Temperature	5,047±5 K
Metallicity [Fe/H]	−0.01±0.10 dex
Age	770±170 Myr
Other designations
b Cap, 36 Cap, BD−22° 5692, HD 204381, HIP 106039, HR 8213, SAO 190374[7]
Database references
SIMBAD	data

This is an evolved G-type giant star with a stellar classification of G7IIIb Fe–1,^[3] where the suffix notation indicates an underabundance of iron found in the spectrum. At the age of 770 million years it has become a red clump giant, meaning it is generating energy through helium fusion at its core. It has 2.26 times the mass of the Sun, but has expanded to 8.6 times its radius. It is radiating 43 times the Sun's luminosity from its photosphere at an effective temperature of 5,047 K.^[6]

Chinese name

In Chinese, 十二國 (Shíer Guó), meaning Twelve States, refers to an asterism which is represent twelve ancient states in the Spring and Autumn period and the Warring States period, consisting of 36 Capricorni, φ Capricorni, ι Capricorni, 37 Capricorni, 35 Capricorni, χ Capricorni, θ Capricorni, 30 Capricorni, 33 Capricorni, ζ Capricorni, 19 Capricorni, 26 Capricorni, 27 Capricorni, 20 Capricorni, η Capricorni and 21 Capricorni.^[9] Consequently, 36 Capricorni itself is represent the state Jin (晉)^[10](or Tsin),^[11] together with κ Herculis in Right Wall of Heavenly Market Enclosure (asterism)^[12]

References

1. 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. Hekker, S.; et al. (August 2006), "Precise radial velocities of giant stars. I. Stable stars", Astronomy and Astrophysics, 454 (3): 943–949, arXiv:astro-ph/0604502, Bibcode:2006A&A...454..943H, doi:10.1051/0004-6361:20064946, S2CID 119529768.
3. Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
4. 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.
5. Liu, Y. J.; et al. (2007), "The abundances of nearby red clump giants", Monthly Notices of the Royal Astronomical Society, 382 (2): 553–66, Bibcode:2007MNRAS.382..553L, doi:10.1111/j.1365-2966.2007.11852.x.
6. Gallenne, A.; Pietrzyński, G.; Graczyk, D.; Nardetto, N.; Mérand, A.; Kervella, P.; Gieren, W.; Villanova, S.; Mennickent, R. E.; Pilecki, B. (2018-08-01), "Fundamental properties of red-clump stars from long-baseline H-band interferometry", Astronomy & Astrophysics, 616: A68, arXiv:1806.09572, doi:10.1051/0004-6361/201833341, ISSN 0004-6361
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. (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
10. Ian Ridpath's Startales - Capricornus the Sea Goat
11. Richard Hinckley Allen: Star Names — Their Lore and Meaning: Capricornus
12. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 24 日