Eta Circini

η Circini
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Circinus
Right ascension 15h 04m 48.18757s
Declination −64° 01′ 52.8641″
Apparent magnitude (V) 5.17
Characteristics
Evolutionary stage red giant branch
Spectral type G8 III
B−V color index +0.93
Astrometry
Radial velocity (Rv)44.8±0.8 km/s
Proper motion (μ) RA: +103.058 mas/yr
Dec.: +8.499 mas/yr
Parallax (π)11.7561±0.0661 mas
Distance277 ± 2 ly
(85.1 ± 0.5 pc)
Absolute magnitude (MV)+0.52
Details
Mass2.90±0.04 M☉
Radius10.68±0.22 R☉
Luminosity78.0±0.8 L☉
Surface gravity (log g)2.7022+0.01
−0.05 cgs
Temperature5,250±4 K
Metallicity [Fe/H]−0.37±0.02 dex
Age414±41 Myr
Other designations
η Cir, CPD−63°3493, HD 132905, HIP 73776, HR 5593, SAO 253005
Database references
SIMBADdata

Eta Circini is a solitary star located in the southern constellation of Circinus. Its name is a Bayer designation that is Latinized from η Circini, and abbreviated Eta Cir or η Cir. This star is faintly visible to the naked eye with an apparent visual magnitude of 5.17. The distance to this star, as determined from an annual parallax shift of 11.8 mas, is around 277 light years. The star is drifting further away from the Sun with a line of sight velocity component of 45 km/s.

This is an evolved G-type giant star with a stellar classification of G8 III. It is 414 million years old with 2.9 times the mass of the Sun and 10.7 times the Sun's radius. The star is radiating 78 times the solar luminosity from its enlarged photosphere at an effective temperature of 5,250 K.

References

  1. 1 2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015 XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875 Gaia DR3 record for this source at VizieR.
  3. 1 2 3 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa, 27: 11, Bibcode:1968MNSSA..27...11C.
  4. 1 2 Houk, Nancy; Cowley, A. P. (1979), University of Michigan Catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  5. 1 2 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
  6. 1 2 Alves, S.; et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society, 448 (3): 2749–2765, arXiv:1503.02556, Bibcode:2015MNRAS.448.2749A, doi:10.1093/mnras/stv189.
  7. ↑ "eta Cir", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-01-18
  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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.