Nu Capricorni

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Nu Capricorni
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Capricornus
Right ascension 20h 20m 39.81562s[1]
Declination −12° 45′ 32.6844″[1]
Apparent magnitude (V) +4.76[2]
Spectral type B9 IV[3] or B9.5 V[4]
U−B color index −0.11[2]
B−V color index −0.04[2]
Radial velocity (Rv) −1.00[5] km/s
Proper motion (μ) RA: +14.74[1] mas/yr
Dec.: −14.32[1] mas/yr
Parallax (π) 12.88 ± 0.27[1] mas
Distance 253 ± 5 ly
(78 ± 2 pc)
Absolute magnitude (MV) +0.32[6]
ν Cap A
Mass 2.37[7] M
Luminosity 87[6] L
Surface gravity (log g) 3.97[7] cgs
Temperature 10,461±356[7] K
Metallicity [Fe/H] −0.15±0.04[6] dex
Rotational velocity (v sin i) 24[8] km/s
Age 115[7] Myr
Other designations
Alshat, ν Cap, 8 Cap, ADS 13714, BD−13° 5642, HD 193432, HIP 100310, HR 7773, SAO 163468, WDS J20207-1246A[9]
Database references

Nu Capricorni, Latinized from ν Capricorni, is a binary star[4] in the southern constellation of Capricornus. Because the star lies near the ecliptic it is subject to occultations by the Moon.[10] It has the traditional name Alshat, from the Arabic الشاة aš-šā[t], meaning the sheep that was to be slaughtered by the adjacent Dabih.[11] The system is approximately 253 light years from Earth.

The primary member, component A, is a blue-white hued B-type main sequence or subgiant star with an apparent magnitude of +4.77. Its companion, component B, is a magnitude 11.8 star located at an angular separation of 54.1 arcseconds from the primary.[4]


  1. ^ a b c d e 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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J. 
  3. ^ Houk, N.; Smith-Moore, M. (1988), Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars, 4, Bibcode:1988MSS...C04....0H. 
  4. ^ a b c 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. 
  5. ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, Bibcode:2006AstL...32..759G, arXiv:1606.08053Freely accessible, doi:10.1134/S1063773706110065. 
  6. ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, Bibcode:2012AstL...38..331A, arXiv:1108.4971Freely accessible, doi:10.1134/S1063773712050015. 
  7. ^ a b c d 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. 
  8. ^ Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, Bibcode:2007A&A...463..671R, arXiv:astro-ph/0610785Freely accessible, doi:10.1051/0004-6361:20065224. 
  9. ^ "nu. Cap -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-13. 
  10. ^ White, Nathaniel M.; Feierman, Barry H. (September 1987), "A Catalog of Stellar Angular Diameters Measured by Lunar Occultation", Astronomical Journal, 94: 751, Bibcode:1987AJ.....94..751W, doi:10.1086/114513. 
  11. ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York: Dover Publications Inc. p. 142. ISBN 0-486-21079-0. Retrieved 2010-12-12.