Astronomy:Gamma Chamaeleontis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 10h 35m 28.10720s[1] |
| Declination | −78° 36′ 28.0321″[1] |
| Apparent magnitude (V) | 4.12[2] |
| Characteristics | |
| Spectral type | K5 III[3] |
| U−B color index | +1.94[2] |
| B−V color index | +1.57[2] |
| Astrometry | |
| Radial velocity (Rv) | −22.4[4] km/s |
| Proper motion (μ) | RA: −37.61[1] mas/yr Dec.: +11.08[1] mas/yr |
| Parallax (π) | 7.81 ± 0.12[1] mas |
| Distance | 418 ± 6 ly (128 ± 2 pc) |
| Absolute magnitude (MV) | −1.43[5] |
| Details | |
| Radius | 67[6] R☉ |
| Luminosity | 864[7] L☉ |
| Temperature | 4,035[7] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gamma Chamaeleontis, Latinized from γ Chamaeleontis, is a solitary[9] star located in the southern circumpolar constellation of Chamaeleon. It can faintly be seen with the naked eye on a dark night, having an apparent visual magnitude of 4.12.[2] Based upon an annual parallax shift of 7.81 mas,[1] it is located around 418 light years from the Sun.
This is an evolved K-type giant star with a stellar classification of K5 III.[3] The measured angular diameter, after correction for limb darkening, is 4.86±0.05 mas.[10] At the estimated distance of the star, this yields a physical size of about 67 times the radius of the Sun.[6] It is a suspected variable star, with an amplitude of 0.01 magnitude.[11] The star radiates 864 times the solar luminosity from its outer atmosphere with an effective temperature of 4,053 K.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode: 1986EgUBV........0M.
- ↑ 3.0 3.1 Houk, N.; Cowley, A. P. (1975), "Catalogue of two-dimensional spectral types for the HD stars", University of Michigan I, Bibcode: 1975mcts.book.....H.
- ↑ Wielen, R. et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb (Astronomisches Rechen-Institut Heidelberg) 35 (35): 1, Bibcode: 1999VeARI..35....1W.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(128\cdot 4.86\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 133.8\cdot R_{\bigodot} \end{align} }[/math]
- ↑ 7.0 7.1 7.2 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ "gam Cha". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=gam+Cha.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R.
- ↑ Eggen, O. J. (1973), "The classification of intrinsic variables. IV. Very-small-amplitude, very-short-period red variables", Astrophysical Journal 184: 793, doi:10.1086/152371, Bibcode: 1973ApJ...184..793E.
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