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] |
Characteristics | |
Spectral type | B9 IV[3] or B9.5 V[4] |
U−B color index | −0.11[2] |
B−V color index | −0.04[2] |
Astrometry | |
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] |
Details | |
ν Cap A | |
Mass | 2.37[7] M☉ |
Luminosity | 87[6] L☉ |
Surface gravity (log g) | 3.97[7] cgs |
Temperature | ±356 10,461[7] K |
Metallicity [Fe/H] | ±0.04 −0.15[6] dex |
Rotational velocity (v sin i) | 24[8] km/s |
Age | 115[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Nu Capricorni (ν Capricorni, abbreviated Nu Cap, ν Cap) is a binary star[4] in the southern constellation of Capricornus. It is 6.6 degrees north of the ecliptic and so is subject to occultations by the Moon.[10] The system is about 253 light-years from the Sun.
The two components are designated Nu Capricorni A (also named Alshat[11]) and B.
Nomenclature
ν Capricorni (Latinised to Nu Capricorni) is the system's Bayer designation. The designations of the two components as Nu Capricorni A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[12]
The system bore the traditional name Alshat, from the Arabic الشاة aš-šā[t], meaning 'the sheep' that was to be slaughtered by the adjacent Beta¹ Capricorni (Dabih).[13] In 2016, the IAU organized a Working Group on Star Names (WGSN)[14] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[15] It approved the name Alshat for the component Nu Capricorni A on 30 June 2017 and it is now so included in the List of IAU-approved Star Names.[11]
Properties
The primary member, Nu Capricorni A, is a blue-white hued B-type main sequence or subgiant star with an apparent magnitude of +4.77. Its companion, Nu Capricorni B, is a magnitude 11.8 star at an angular separation of 54.1 arcseconds from the primary.[4]
References
- 1 2 3 4 5 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.
- 1 2 3 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.
- ↑ Houk, N.; Smith-Moore, M. (1988), Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars, 4, Bibcode:1988mcts.book.....H.
- 1 2 3 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.
- ↑ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065.
- 1 2 3 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.
- 1 2 3 4 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, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
- ↑ Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
- ↑ "nu. Cap". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-05-13.
- ↑ 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.
- 1 2 "Naming Stars". IAU.org. Retrieved 16 December 2017.
- ↑ Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
- ↑ 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.
- ↑ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
- ↑ "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Retrieved 2018-07-14.