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.
| 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] |
| Distance | 215 ± 7 ly (66 ± 2 pc) |
| Absolute magnitude (MV) | +1.76[6] |
| Details[7] | |
| σ2 Gru A | |
| Mass | 2.15 M☉ |
| Luminosity | 17.5[6] L☉ |
| Surface gravity (log g) | 4.36±0.14 cgs |
| Temperature | 9,549±325 K |
| Rotational velocity (v sin i) | 80.9±0.7[8] km/s |
| Age | 255 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
References
edit- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "* sig02 Gru". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-24.
{{cite web}}: CS1 maint: postscript (link) - ^ 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.