Alpha Chamaeleontis

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α Chamaeleontis
Observation data
Epoch J2000.0      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 F5VFe-0.8[3]
U−B color index −0.04[2]
B−V color index +0.40[2]
Astrometry
Proper motion (μ) RA: −0.13[1] mas/yr
Dec.: +6.89[1] mas/yr
Parallax (π) 51.12 ± 0.12[1] mas
Distance 63.8 ± 0.1 ly
(19.56 ± 0.05 pc)
Details
Mass 1.42[4] M
Luminosity 7.64[5] L
Surface gravity (log g) 4.28±0.14[4] cgs
Temperature 6,776±230[4] K
Metallicity [Fe/H] −0.26[3] dex
Rotational velocity (v sin i) 0[6] km/s
Age 1.8[4] Gyr
Other designations
α Cha, CPD−76° 507, Gliese 305, HD 71243, HIP 40702, HR 3318, SAO 256496.[7]
Database references
SIMBAD data

Alpha Chamaeleontis (α Cha, α Chamaeleontis) is a solitary[8] 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.

This is an F-type main sequence star with a stellar classification of F5 V Fe−0.8,[3] where 'Fe−0.8' indicates an anomalously low abundance of iron. It has an estimated 1.4 times the mass of the Sun,[4] and radiates 7.64[5] times the solar luminosity from its outer atmosphere at an effective temperature of 6,776 K.[4] The star is around 1.8[4] billion years old with a projected rotational velocity that is too low to be measured.[6] The star has been examined for an infrared excess that would suggest the presence of an orbiting debris disk, but none was found.[9]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ a b c 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, Bibcode:2006AJ....132..161G, arXiv:astro-ph/0603770Freely accessible, doi:10.1086/504637. 
  4. ^ a b c d e f g 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, Bibcode:2015ApJ...804..146D, arXiv:1501.03154Freely accessible, doi:10.1088/0004-637X/804/2/146. 
  5. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037Freely accessible, doi:10.1111/j.1365-2966.2012.21873.x. 
  6. ^ a b 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. 
  7. ^ "alf Cha -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-12-10. 
  8. ^ 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, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  9. ^ Gáspár, András; et al. (May 2013), "The Collisional Evolution of Debris Disks", The Astrophysical Journal, 768 (1): 29, Bibcode:2013ApJ...768...25G, arXiv:1211.1415Freely accessible, doi:10.1088/0004-637X/768/1/25, 25.