Alpha Antliae

Coordinates: Sky map 10h 27m 09.1011s, −31° 04′ 04.004″
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α Antliae
Antlia constellation map.svg
Location of α Antliae to the upper left of center
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Antlia
Right ascension 10h 27m 09.10313s[1]
Declination −31° 04′ 03.9830″[1]
Apparent magnitude (V) 4.25[2] (4.22 to 4.29[3])
Spectral type K4 III[4]
U−B color index +1.63[5]
B−V color index +1.45[5]
R−I color index +0.79[5]
Variable type Suspected[3]
Radial velocity (Rv)12.2 ± 2[6] km/s
Proper motion (μ) RA: −83.34±0.49[1] mas/yr
Dec.: +8.27±0.48[1] mas/yr
Parallax (π)10.0734 ± 0.3348 mas[1]
Distance320 ± 10 ly
(99 ± 3 pc)
Absolute magnitude (MV)−0.97[7]
Mass2.2[8] M
Radius41[1] R
Luminosity (bolometric)412[1] L
Surface gravity (log g)1.77[9] cgs
Temperature4,070[1] K
Metallicity [Fe/H]-0.39[9] dex
Other designations
α Ant, Alpha Antliae, Alpha Ant, 2MASS J10270911-3104039, CD−30 8465, CPC 17 5084, CPD−30 3121, FK5 392, GC 14352, HD 90610, HIP 51172, HR 4104, NSV 4862, PPM 287713, SAO 201405[10]
Database references

Alpha Antliae (Alpha Ant, α Antliae, α Ant) is the brightest star in the constellation of Antlia but it has not been given a proper name.[11] It is approximately 320 light-years from the Solar System. It is a K-type giant star with an apparent visual magnitude of 4.25. This star has 2.2 times the mass of the Sun and has expanded to 41 times the solar radius. Compared to the Sun, it has only 41% of the abundance of elements other than hydrogen and helium.

α Antliae has been reported to vary in brightness between magnitude 4.22 and 4.29, first in 1879 by Benjamin Gould, but this has not been confirmed in modern times.[3] The evolutionary state of α Antliae isn't clear but it is suspected of being on the asymptotic giant branch, with an inert carbon core.[8]


  1. ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ Hoffleit, Dorrit; Jaschek, Carlos (1991). "The Bright star catalogue". New Haven.
  3. ^ a b c NSV 4862, database entry, New Catalogue of Suspected Variable Stars, the improved version, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line October 3, 2008.
  4. ^ Houk, Nancy (1983). Michigan catalogue of two-dimensional spectral types for the HD stars. Michigan Spectral Survey. Vol. 3. University of Michigan. Retrieved 2009-10-22.
  5. ^ a b c Hoffleit, D.; Warren, Jr., W. H. "HR 4104". The Bright Star Catalogue (5th revised ed.). Centre de Données astronomiques de Strasbourg. Retrieved 2008-10-03.
  6. ^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.
  7. ^ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256.
  8. ^ a b Alpha Antliae, Stars, Jim Kaler. Accessed on line October 3, 2008.
  9. ^ a b McWilliam, Andrew (December 1990). "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances". Astrophysical Journal Supplement Series. 74: 1075–1128. Bibcode:1990ApJS...74.1075M. doi:10.1086/191527.
  10. ^ "alf Ant". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 3, 2008.
  11. ^ Schneider, Howard; Wood, Sandy (2009). National Geographic Backyard Guide to the Night Sky. National Geographic Books. p. 173. ISBN 978-1-4262-0281-0.