Sigma2 Gruis is a binary star[3] system in the southern constellation of Grus. Its apparent visual magnitude is 5.86.[2] The pair had an angular separation of 2.7 arc seconds along a position angle of 265°, as of 1991.[10] Located around 215 ly (66 pc) distant, the white-hued primary component is an A-type main-sequence star of spectral type A1V,[4] a star that is currently fusing its core hydrogen.

Sigma2 Gruis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Grus
Right ascension 22h 36m 58.85405s[1]
Declination −40° 35′ 27.7272″[1]
Apparent magnitude (V) 5.86[2] (5.91 + 10.04)[3]
Characteristics
Spectral type A1 V[4]
U−B color index +0.06[2]
B−V color index +0.06[2]
Astrometry
Radial velocity (Rv)+15.0±2.9[5] km/s
Proper motion (μ) RA: +44.56[1] mas/yr
Dec.: −70.07[1] mas/yr
Parallax (π)15.19 ± 0.53 mas[1]
Distance215 ± 7 ly
(66 ± 2 pc)
Absolute magnitude (MV)+1.76[6]
Details[7]
σ2 Gru A
Mass2.15 M
Luminosity17.5[6] L
Surface gravity (log g)4.36±0.14 cgs
Temperature9,549±325 K
Rotational velocity (v sin i)80.9±0.7[8] km/s
Age255 Myr
Other designations
σ2 Gru, CD−41° 14963, HD 214150, HIP 111643, HR 8602, SAO 231217, WDS J22370-4035[9]
Database references
SIMBADdata

References

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  1. ^ a b c d e 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 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
  3. ^ a b 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.
  4. ^ a b Houk, N. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  5. ^ Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
  6. ^ a b 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.
  7. ^ 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, S2CID 33401607.
  8. ^ Díaz, C. G.; et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics, 531: A143, arXiv:1012.4858, Bibcode:2011A&A...531A.143D, doi:10.1051/0004-6361/201016386, S2CID 119286673.
  9. ^ "* sig02 Gru". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-24.{{cite web}}: CS1 maint: postscript (link)
  10. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.