Eta Antliae

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Eta Antliae
Diagram showing star positions and boundaries of the Antlia constellation and its surroundings
Cercle rouge 100%.svg

Location of η Antliae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Antlia
Right ascension 09h 58m 52.27556s[1]
Declination –35° 53′ 27.5098″[1]
Apparent magnitude (V) 5.222[2]
Spectral type F1 V[3]
U−B color index +0.068[2]
B−V color index +0.333[2]
Radial velocity (Rv) +30[4] km/s
Proper motion (μ) RA: –89.65[1] mas/yr
Dec.: –17.23[1] mas/yr
Parallax (π) 30.02 ± 0.24[1] mas
Distance 108.6 ± 0.9 ly
(33.3 ± 0.3 pc)
η Ant A
Mass 1.55[5] M
Luminosity 6.6[5] L
Surface gravity (log g) 3.94[3] cgs
Temperature 7,132[3] K
Metallicity [Fe/H] –0.20[3] dex
Age 0.9[5] Gyr
Other designations
CD–35 6050, FK5 377, HD 86629, HIP 48926, HR 3947, SAO 200926.[6]
Database references
Database references

Eta Antliae (η Ant, η Antliae) is the Bayer designation for a double star in the southern constellation of Antlia. The brighter component has an apparent visual magnitude of 5.222,[2] making it visible to the naked eye. Parallax measurements of the system yield a distance estimate of 108.6 light-years (33.3 parsecs) from Earth.[1]

The main component has a stellar classification of F1 V,[3] which indicates that it is an F-type main sequence star. This star has 55% more mass than the Sun.[5] It shines with 6.6[5] times the Sun's luminosity at an effective temperature of 7,132 K.[3] This heat gives it the yellow-white glow of an F-type star.[7] It has a faint companion located 31 arcseconds away with an apparent magnitude of +11.3. Most likely this pair form a binary star system.[8]


  1. ^ a b c d e f van Leeuwen, F. (November 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 Gutierrez-Moreno, Adelina; et al. (1966), A System of photometric standards, 1, Publicaciones Universidad de Chile, Department de Astronomy, pp. 1–17, Bibcode:1966PDAUC...1....1G. 
  3. ^ a b c d e f Gray, R. O.; et al. (July 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): 161–170, Bibcode:2006AJ....132..161G, arXiv:astro-ph/0603770Freely accessible, doi:10.1086/504637. 
  4. ^ Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W. 
  5. ^ a b c d e Mallik, Sushma V.; Parthasarathy, M.; Pati, A. K. (October 2003), "Lithium and rotation in F and G dwarfs and subgiants", Astronomy and Astrophysics, 409: 251–261, Bibcode:2003A&A...409..251M, doi:10.1051/0004-6361:20031084. 
  6. ^ "eta Ant -- Star in double system", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-06-28. 
  7. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-10, retrieved 2012-01-16. 
  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.