Delta Columbae

δ Columbae

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Columba
Right ascension	06^h 22^m 06.82831^s[1]
Declination	−33° 26′ 11.0323″[1]
Apparent magnitude (V)	3.85[2]
Characteristics
Spectral type	G7 II[3]
U−B color index	+0.52[2]
B−V color index	+0.88[2]
Astrometry
Proper motion (μ)	RA: −24.23[1] mas/yr Dec.: −51.40[1] mas/yr
Parallax (π)	13.94 ± 0.51 mas[1]
Distance	234 ± 9 ly (72 ± 3 pc)
Absolute magnitude (MV)	−0.32[4]
Orbit[5][6]
Period (P)	868.78 d
Semi-major axis (a)	9.02±0.52 mas
Eccentricity (e)	0.7
Inclination (i)	116.3±4.2°
Periastron epoch (T)	2419915.02 JD
Argument of periastron (ω) (secondary)	117.1°
Semi-amplitude (K1) (primary)	10.6 km/s
Details
δ Col A
Luminosity	149.5[7] L☉
Surface gravity (log g)	2.49[8] cgs
Temperature	5,136[4] K
Metallicity [Fe/H]	−0.04[8] dex
Rotational velocity (v sin i)	4.8±0.2[4] km/s
Other designations
δ Col, CD−33° 2927, HD 44762, HIP 30277, HR 2296, SAO 196735.[9]
Database references
SIMBAD	data

Delta Columbae is a binary star system in the constellation Columba. It can be seen with the naked eye having an apparent visual magnitude of 3.85.^[2] The distance to this system, based upon an annual parallax shift of 13.94 mas,^[1] is around 234 lightyears.

Delta Columbae was a latter designation of 3 Canis Majoris, as the early astronomers Johann Bayer and John Flamsteed did not include the constellation Columba in their star charts.^[10] It has the uncommon traditional name Ghusn al Zaitun, from the Arabic الغصن الزيتون al-ghuşn al-zaitūn "the olive branch" (carried by the dove of Noah's Ark).^{[citation needed]}

This is a single-lined spectroscopic binary system with an orbital period of 868.78 days and an eccentricity of 0.7.^[5] It has a peculiar velocity of 30.2±3.9 km/s, making it a candidate runaway star system. The primary component is a G-type bright giant star with a stellar classification of G7 II.^[3] It radiates around 149^[7] time the solar luminosity from its outer atmosphere at an effective temperature of 5,136 K.^[4]

References

1. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
2. Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1999), "UBVRIJKL photometry of the bright stars", Commission Lunar and Planetary Laboratory, 4: 99, Bibcode:1966CoLPL...4...99J.
3. Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
4. Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
5. Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "S_B⁹: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
6. Jancart, S.; et al. (October 2005), "Astrometric orbits of S_B⁹ stars", Astronomy and Astrophysics, 442 (1): 365–380, arXiv:astro-ph/0507695, Bibcode:2005A&A...442..365J, doi:10.1051/0004-6361:20053003, S2CID 15123997.
7. McDonald, I.; et al. (2012). "Fundamental Parameters and Infrared Excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–57. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352.
8. Luck, R. Earle (2014), "Parameters and Abundances in Luminous Stars", The Astronomical Journal, 147 (6): 137, Bibcode:2014AJ....147..137L, doi:10.1088/0004-6256/147/6/137.
9. "del Col -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-12-21.
10. Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy, 18 (3): 209–223, Bibcode:1987JHA....18..209W, doi:10.1177/002182868701800305, S2CID 118445625.