Lambda Columbae is a probable binary star[10] in the southern constellation of Columba. Its name is a Bayer designation that is Latinized from λ Columbae, and abbreviated Lambda Columbae or λ Col. With an apparent visual magnitude of 4.88,[4] it is faintly visible to the naked eye. The measured annual parallax shift of 9.47 mas[2] yields an estimated distance of approximately 345 light-years (106 pc). It is drifting further away from the Sun with a line of sight velocity component of +30 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba[1] |
| Right ascension | 05h 53m 06.882s[2] |
| Declination | −33° 48′ 04.91″[2] |
| Apparent magnitude (V) | 4.88[1] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | B5 V[3] |
| U−B color index | −0.57[4] |
| B−V color index | −0.154±0.008[1] |
| Variable type | Suspected rotating ellipsoidal[5] |
| Astrometry | |
| Radial velocity (Rv) | +30.0[6] km/s |
| Proper motion (μ) | RA: −4.095 mas/yr[2] Dec.: +31.125 mas/yr[2] |
| Parallax (π) | 9.466±0.0901 mas[2] |
| Distance | 345 ± 3 ly (106 ± 1 pc) |
| Absolute magnitude (MV) | −0.17[1] |
| Details | |
| Mass | 4.26±0.04[2] M☉ |
| Radius | 2.72±0.06[2] R☉ |
| Luminosity | 343±6[2] L☉ |
| Surface gravity (log g) | 4.0513±0.009[2] cgs |
| Temperature | 15,057+30 −25[2] K |
| Metallicity [Fe/H] | −0.06[7] dex |
| Rotational velocity (v sin i) | 88[8] km/s |
| Age | 56.6±26.1[3] Myr |
| Other designations | |
| λ Col, CD−33°2599, HD 39764, HIP 27810, HR 2056, SAO 196276[9] | |
| Database references | |
| SIMBAD | data |

Lambda Columbae has a stellar classification of B5 V,[3] indicating that it is a B-type main sequence star. It is a suspected rotating ellipsoidal variable[12] with a period of 0.64 days and an amplitude of 0.07 magnitude.[13] Confirmation would indicate that this is a close binary system.[5]
This star has an estimated age of around 57 million years[3] with a relatively high rate of spin, showing a projected rotational velocity of 88 km/s.[8] It has 4.3 times the mass of the Sun and 2.7 times the Sun's radius. Lambda Columbae is radiating 343 times the luminosity of the Sun from its photosphere at an effective temperature of 15,057 K.[2]
In Chinese, 子 (Zǐ), meaning Son, refers to an asterism consisting of λ Columbae and β Columbae.[14] Consequently, λ Columbae itself is known as 子一 (Zǐ yī, English: the First Star of Son).[15] From this Chinese name, the name Tsze is derived.[16]
References
edit- 1 2 3 4 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.
- 1 2 3 4 5 6 7 8 9 10 11 12 13 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.
- 1 2 3 4 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.
- 1 2 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", SIMBAD, Bibcode:1986EgUBV........0M.
- 1 2 Samus, N.N.; Durlevich, O.V.; et al. (March 2012), General Catalog of Variable Stars, Institute of Astronomy of Russian Academy of Sciences and Sternberg State Astronomical Institute of the Moscow State University.
- 1 2 Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W.
- ↑ Hempel, M.; Holweger, H. (September 2003), "Abundance analysis of late B stars. Evidence for diffusion and against weak stellar winds", Astronomy and Astrophysics, 408: 1065–1076, Bibcode:2003A&A...408.1065H, doi:10.1051/0004-6361:20030889.
- 1 2 Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.
- ↑ "lam Col", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2016-12-26.
- ↑ 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.
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 31 December 2022.
- ↑ Morris, S. L. (August 1985), "The ellipsoidal variable stars", Astrophysical Journal, Part 1, 295: 143–152, Bibcode:1985ApJ...295..143M, doi:10.1086/163359.
- ↑ Hoffleit, Dorrit (1996), "A Catalogue of Correlations Between Eclipsing Binaries and Other Categories of Double Stars", The Journal of the American Association of Variable Star Observers, 24 (2): 105–116, Bibcode:1996JAVSO..24..105H.
- ↑ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 16 日 Archived 2011-08-22 at the Wayback Machine
- ↑ Allen, Richard Hinckley (1963), "Columba Noae, Noah's Dove", Star Names: their Lore and Meaning (Dover ed.).