Astronomy:Alpha Chamaeleontis
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 08h 18m 31.55319s[1] |
| Declination | −76° 55′ 10.9964″[1] |
| Apparent magnitude (V) | 4.06[2] |
| Characteristics | |
| Spectral type | F5 V Fe-0.8[3] |
| U−B color index | −0.04[2] |
| B−V color index | +0.40[2] |
| Astrometry | |
| Radial velocity (Rv) | −13.4±0.5[4] km/s |
| Proper motion (μ) | RA: 111.12[1] mas/yr Dec.: 107.49[1] mas/yr |
| Parallax (π) | 51.12 ± 0.12[1] mas |
| Distance | 63.8 ± 0.1 ly (19.56 ± 0.05 pc) |
| Absolute magnitude (MV) | +2.59[5] |
| Details | |
| Mass | 1.42[6] M☉ |
| Radius | 2.11+0.14 −0.05[7] R☉ |
| Luminosity | 7.542±0.062[7] L☉ |
| Surface gravity (log g) | 4.28±0.14[6] cgs |
| Temperature | 6,580+91 −209[7] K |
| Metallicity [Fe/H] | −0.26[3] dex |
| Rotational velocity (v sin i) | 0[8] km/s |
| Age | 1.8[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Alpha Chamaeleontis, Latinized from α Chamaeleontis, is a solitary[10] star in the southern circumpolar constellation of Chamaeleon. It has an apparent visual magnitude of 4.06[2] and thus is bright enough to be seen with the naked eye. With an annual parallax shift of 51.12 mas,[1] it is located 63.8 light years from the Sun. The star is drifting closer with a radial velocity of −13 km/s,[4] and is predicted to come to within 47 light-years in 666,000 years.[5]
This is an F-type main sequence star with a stellar classification of F5 V Fe−0.8,[3] where the 'Fe−0.8' notation indicates an anomalously low abundance of iron. It has an estimated 1.4 times the mass of the Sun,[6] 2.1 times the Sun's radius,[7] and radiates 7.5 times the solar luminosity from its outer atmosphere at an effective temperature of 6,580 K.[7] The star is around 1.8[6] billion years old with a projected rotational velocity that is too low to be measured.[8] The star has been examined for an infrared excess that would suggest the presence of an orbiting debris disk, but none was found.[11]
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- ↑ 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode: 1986EgUBV........0M.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 3.2 Gray, R. O. et al. (2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–70, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
- ↑ 4.0 4.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 5.0 5.1 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 6.2 6.3 6.4 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, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 7.0 7.1 7.2 7.3 7.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 8.0 8.1 Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory (University of Kyoto), Bibcode: 1970crvs.book.....U.
- ↑ "alf Cha". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=alf+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.
- ↑ Gáspár, András et al. (May 2013), "The Collisional Evolution of Debris Disks", The Astrophysical Journal 768 (1): 29, doi:10.1088/0004-637X/768/1/25, 25, Bibcode: 2013ApJ...768...25G.
 |  |
