Edge Rewrite
Jump to content

Eta Columbae

From Wikipedia, the free encyclopedia
η Columbae
Location of η Columbae (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Columba
Right ascension 05h 59m 08.805s[1]
Declination −42° 48 54.48[1]
Apparent magnitude (V) 3.96[2]
Characteristics
Spectral type G8/K1 II[3] or K0 III[4]
U−B color index +1.08[2]
B−V color index +1.14[2]
Astrometry
Radial velocity (Rv)+17.0[4] km/s
Proper motion (μ) RA: +118.897 mas/yr[1]
Dec.: −11.038 mas/yr[1]
Parallax (π)7.4021±0.1207 mas[1]
Distance441 ± 7 ly
(135 ± 2 pc)
Absolute magnitude (MV)−2.10[5]
Details
Mass4.70±0.04[1] M
Radius35.6±0.9[1] R
Luminosity564+18
16
[1] L
Surface gravity (log g)1.799±0.013[1] cgs
Temperature4,715+4
5
[1] K
Metallicity [Fe/H]−0.01[4] dex
Other designations
η Col, CD−42°2266, FK5 229, HD 40808, HIP 28328, HR 2120, SAO 217650[6]
Database references
SIMBADdata

Eta Columbae is a solitary[7] star near the southern boundary of the constellation Columba.[8] Its name is a Bayer designation that is Latinized from η Columbae, and abbreviated Eta Col or η Col. This star is visible to the naked eye, having an apparent visual magnitude of 3.96.[2] Based upon an annual parallax shift of 7.40 mas,[1] it lies at a distance of approximately 441 light-years (135 pc) from the Sun. It is drifting further away with a line of sight velocity component of +17 km/s.[4]

This is an orange-hued[8] K-type giant star with a stellar classification of K0 III,[4] or possibly a bright giant with a crossover class of G8/K1 II.[3] It has an estimated 4.7 times the mass of the Sun and has expanded to 35.6 times the Sun's radius. This star is radiating 564 times the solar luminosity from its photosphere at an effective temperature of 4,715 K.[1]

References

[edit]
  1. 1 2 3 4 5 6 7 8 9 10 11 12 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.
  2. 1 2 3 4 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  3. 1 2 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  4. 1 2 3 4 5 Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal. 150 (3): 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. S2CID 118505114.
  5. Böhm-Vitense, Erika; et al. (December 2000), "Ultraviolet Emission Lines in BA and Non-BA Giants", The Astrophysical Journal, 545 (2): 992–999, Bibcode:2000ApJ...545..992B, doi:10.1086/317850.
  6. "eta Col", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2016-12-23.
  7. 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.
  8. 1 2 Kambic, Bojan (2009), Viewing the Constellations with Binoculars: 250+ Wonderful Sky Objects to See and Explore, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 260, ISBN 978-0387853550.