Mu Capricorni

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Mu Capricorni
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Capricornus
Right ascension 21h 53m 17.77054s[1]
Declination −13° 33′ 06.3679″[1]
Apparent magnitude (V) +5.081[2]
Spectral type F2 V[3]
U−B color index +0.012[2]
B−V color index +0.367[2]
Proper motion (μ) RA: +311.22[1] mas/yr
Dec.: +13.46[1] mas/yr
Parallax (π) 37.57 ± 0.67[1] mas
Distance 87 ± 2 ly
(26.6 ± 0.5 pc)
Absolute magnitude (MV) +2.96±0.04[4]
Mass 1.29[5] M
Radius 1.8[6] R
Surface gravity (log g) 4.28[5] cgs
Temperature 6,892±234[5] K
Metallicity [Fe/H] −0.14[4] dex
Rotational velocity (v sin i) 69.3±3.5[7] km/s
Age 1.6±0.3[4] Gyr
Other designations
μ Cap, 51 Cap, BD−14° 6149, FK5 1577, Gl 838.5, HD 207958, HIP 108036, HR 8351, SAO 164713[8]
Database references

Mu Capricorni (μ Cap, μ Capricorni) is a solitary[9] star in the southern constellation of Capricornus. Based upon an annual parallax shift of 37.57 mas as seen from the Earth,[1] the star is located about 87 light years from the Sun. It is visible to the naked eye with an apparent visual magnitude of +5.081.[2]

This is a yellow-white hued, F-type main sequence star with a stellar classification of F2 V.[3] It is an estimated 1.6[4] billion years old and is spinning with a projected rotational velocity of 69 km/s.[7] The star has 1.29[5] times the mass of the Sun and around 1.8[6] times the Sun's radius, with an effective temperature of 6,892 K.[5]

In Chinese, (), meaning Crying, refers to an asterism consisting of μ Capricorni and 38 Aquarii.[10] Consequently, μ Capricorni itself is known as 哭一 (Kū yī, English: the First Star of Crying.).[11] From this Chinese name, the name Kuh was appeared.[12]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Gutierrez-Moreno, A.; et al. (1966), "A system of photometric standards", Publicaciones Departamento de Astronomia, Universidad de Chile, 1, Bibcode:1966PDAUC...1....1G. 
  3. ^ a b Gray, R. O.; et al. (2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample", The Astronomical Journal, 132: 161, Bibcode:2006AJ....132..161G, arXiv:astro-ph/0603770Freely accessible, doi:10.1086/504637. 
  4. ^ a b c d Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, Bibcode:2009A&A...501..941H, arXiv:0811.3982Freely accessible, doi:10.1051/0004-6361/200811191. 
  5. ^ a b c d e David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, Bibcode:2015ApJ...804..146D, arXiv:1501.03154Freely accessible, doi:10.1088/0004-637X/804/2/146. 
  6. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (3rd ed.), 367: 521–524, Bibcode:2001A&A...367..521P, arXiv:astro-ph/0012289Freely accessible, doi:10.1051/0004-6361:20000451. 
  7. ^ a b Reiners, A. (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, Bibcode:2006A&A...446..267R, arXiv:astro-ph/0509399Freely accessible, doi:10.1051/0004-6361:20053911. 
  8. ^ "mu. Cap -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-13. 
  9. ^ 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, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  10. ^ (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.
  11. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 5 日
  12. ^ Allen, Richard Hinckley (1963), "Capricornus", Star Names, Their Lore and Meaning, Dover, retrieved 2017-05-09.