Gamma Circini
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 23m 22.64294s[1] |
| Declination | −59° 19′ 14.8131″[1] |
| Apparent magnitude (V) | 4.51[2] (4.94 + 5.73)[3] |
| Characteristics | |
| Spectral type | B5 IV[4] + F8 V[2] |
| Variable type | Be[5] |
| Astrometry | |
| Radial velocity (Rv) | 16.90±1.78[6] km/s |
| Proper motion (μ) | RA: −12.97[1] mas/yr Dec.: −34.24[1] mas/yr |
| Parallax (π) | 7.27 ± 0.81 mas[1] |
| Distance | approx. 450 ly (approx. 140 pc) |
| Absolute magnitude (MV) | −1.18[7] |
| Orbit[4] | |
| Period (P) | 258 yr |
| Semi-major axis (a) | 2.576″ |
| Eccentricity (e) | 0.931 |
| Details | |
| γ Cir A | |
| Mass | 6.0±0.3[8] M☉ |
| Temperature | 15,135[9] K |
| Age | 63.1±19.6[8] Myr |
| γ Cir B | |
| Temperature | 4,786[9] K |
| Other designations | |
| γ Cir A: HD 136415 | |
| γ Cir B: HD 136416 | |
| Database references | |
| SIMBAD | γ Cir AB |
| γ Cir A | |
| γ Cir B | |
Gamma Circini, Latinized from γ Circini, is a star system in the constellation Circinus. It was noted as a double star by Herschel in 1835, who estimated the separation as 1 arc second.[11] It is visible to the naked eye with an apparent visual magnitude of 4.51.[2] Based upon an annual parallax shift of 7.27 mas,[1] it is about 450 light-years away.
This is a wide binary star system and may even be a triple star.[9] The two visible components orbit each other with a preliminary estimated period of 258 years and a large eccentricity of 0.931.[4] As of 2014, the visible components have an angular separation of 0.80 arc seconds on a position angle of 359°.[3]
The primary star, component A, is a B-type subgiant star with a stellar classification of B5 IV.[4] Based upon isochrone curve fitting it is hypothesized to be a pair of matching B5 stars,[9] and is a Be variable with an uncertain maximum.[5] It has an effective temperature of 15,135[9] K and an estimated mass six[8] times that of the Sun. The companion, component B, is an F-type main-sequence star with a stellar classification of F8 V.[2] It has an effective temperature of 4,786[9] K.
References
[edit]- ^ a b c d e f 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 Buscombe, W.; Barkstrom, B. (1971), "The composite spectrum of gamma Circini", Monthly Notices of the Royal Astronomical Society, 152: 37–45, Bibcode:1971MNRAS.152...37B, doi:10.1093/mnras/152.1.37.
- ^ a b Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22
- ^ a b c d Malkov, O. Yu.; et al. (2012), "Dynamical masses of a selected sample of orbital binaries", Astronomy & Astrophysics, 546: A69, Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774.
- ^ a b Kazarovets, E. V.; et al. (1999). "The 74th Special Name-list of Variable Stars". Information Bulletin on Variable Stars. 4659: 1. Bibcode:1999IBVS.4659....1K.
- ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ 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.
- ^ a b c Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ a b c d e f Parsons, Sidney B. (May 2004), "New and Confirmed Triple Systems with Luminous Cool Primaries and Hot Companions", The Astronomical Journal, 127 (5): 2915–2930, Bibcode:2004AJ....127.2915P, doi:10.1086/383546.
- ^ "* gam Cir". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-13.
{{cite web}}: CS1 maint: postscript (link) - ^ Carette, E.; et al. (April 1995), "γ Circinus: a young visual binary with pre-main-sequence component(s)?", Astronomy and Astrophysics, 296: 139, Bibcode:1995A&A...296..139C.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 29 December 2022.
