# Lambda Centauri

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Star in the constellation Centaurus

λ Centauri Location of λ Centauri, circled, lower right Observation data Epoch J2000.0 Equinox J2000.0 Constellation Centaurus Right ascension 11h 35m 46.878s[1] Declination −63° 01′ 11.41″[1] Apparent magnitude (V) +3.13[2] Characteristics Spectral type B9 III[3][4] U−B color index −0.19[2] B−V color index −0.04[2] Astrometry Radial velocity (Rv) −1.4[5] km/s Proper motion (μ) RA: −33.863 mas/yr[1] Dec.: −7.236 mas/yr[1] Parallax (π) 8.2770±0.2537 mas[1] Distance 390 ± 10 ly (121 ± 4 pc) Absolute magnitude (MV) −2.35[6] Details Mass 4.5[7] M☉ Radius 5.5[8] R☉ Luminosity 739[9] L☉ Surface gravity (log g) 3.04[10] cgs Temperature 9,880[11] K Metallicity [Fe/H] +0.41[10] dex Rotational velocity (v sin i) 183[12] km/s Other designations λ Cen, lambda Cen, CPD−62°2127, FK5 436, HD 100841, HIP 56561, HR 4467, SAO 251472[13] Database references SIMBAD data

λ Centauri in [IC 2944](/source/IC_2944), with IC 2948 below left and IC 2872 above right

**Lambda Centauri** is a [star](/source/Star) in the southern [circumpolar constellation](/source/Circumpolar_constellation) of [Centaurus](/source/Centaurus). Its name is a [Bayer designation](/source/Bayer_designation) that is [Latinized](/source/Romanization_of_Greek) from λ Centauri, and abbreviated Lambda Cen or λ Cen. The star has an [apparent visual magnitude](/source/Apparent_visual_magnitude) of +3.13,[2] which is bright enough to be seen with the [naked eye](/source/Naked_eye) from the [Southern Hemisphere](/source/Southern_Hemisphere) and places it among the brighter members of this constellation. The star is close enough that its distance can be determined directly using the [parallax](/source/Stellar_parallax) technique, which gives a value of approximately 390 [light years](/source/Light_year) (121 [pc](/source/Parsec)) from the [Sun](/source/Sun). Although a putative solitary star, it has a candidate proper motion companion at an [angular separation](/source/Angular_separation) of 0.73 [arcseconds](/source/Arcsecond) along a [position angle](/source/Position_angle) of 135°.[14] The [nebula](/source/Nebula) [IC 2944](/source/IC_2944) lies nearby.[15]

Lambda Centauri is a [B-type](/source/Stellar_classification) [giant star](/source/Giant_star)[16] with a [stellar classification](/source/Stellar_classification) of B9 III[3] (although it has also been classified as A1 III).[11] It has about 5.5[8] times the radius of the [Sun](/source/Sun) and is rotating rapidly with a [projected rotational velocity](/source/Projected_rotational_velocity) of 183 km/s.[12] The latter is giving the star an [oblate](/source/Oblate_spheroid) shape with an [equatorial bulge](/source/Equatorial_bulge) that is 17% larger than the polar radius.[17] The star's [outer atmosphere](/source/Stellar_atmosphere) has an [effective temperature](/source/Effective_temperature) of 9,880 K,[11] giving it a blue-white hue.

Based upon the position and movement of this star through space, it is a likely member of the [Gould Belt](/source/Gould_Belt). In particular, it belongs to the Lower Centaurus–Crux (LCC) group of the [Scorpius–Centaurus association](/source/Scorpius%E2%80%93Centaurus_association), which is the nearest [OB association](/source/OB_association) to the Sun. This is a loose grouping of stars that share a common motion through space and therefore formed in the same [molecular cloud](/source/Molecular_cloud). The LCC group has an estimated age of 16–20 million years and is centered on a mean distance of 380 light-years (120 parsecs) from Earth.[18]

## Gallery

		- Lambda Centauri and surrounding nebula [IC 2944](/source/IC_2944)

		- [Crux](/source/Crux) with λ Centauri (top) and its associated nebulosity visible

## References

1. ^ [***a***](#cite_ref-GaiaDR3_1-0) [***b***](#cite_ref-GaiaDR3_1-1) [***c***](#cite_ref-GaiaDR3_1-2) [***d***](#cite_ref-GaiaDR3_1-3) Vallenari, A.; et al. (Gaia collaboration) (2023), ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940), *Astronomy and Astrophysics*, **674**: A1, [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211), [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940), [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D5333974693006467328%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-clpl4_2-0) [***b***](#cite_ref-clpl4_2-1) [***c***](#cite_ref-clpl4_2-2) [***d***](#cite_ref-clpl4_2-3) Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", *Communications of the Lunar and Planetary Laboratory*, **4** (99): 99, [Bibcode](/source/Bibcode_(identifier)):[1966CoLPL...4...99J](https://ui.adsabs.harvard.edu/abs/1966CoLPL...4...99J).

1. ^ [***a***](#cite_ref-houk1979_3-0) [***b***](#cite_ref-houk1979_3-1) Houk, Nancy (1979), "Michigan catalogue of two-dimensional spectral types for the HD stars", *Ann Arbor: Dept. Of Astronomy*, **1**, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, [Bibcode](/source/Bibcode_(identifier)):[1978mcts.book.....H](https://ui.adsabs.harvard.edu/abs/1978mcts.book.....H)

1. **[^](#cite_ref-mnras389_2_869_4-0)** 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](/source/ArXiv_(identifier)):[0806.2878](https://arxiv.org/abs/0806.2878), [Bibcode](/source/Bibcode_(identifier)):[2008MNRAS.389..869E](https://ui.adsabs.harvard.edu/abs/2008MNRAS.389..869E), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2008.13596.x](https://doi.org/10.1111%2Fj.1365-2966.2008.13596.x), [S2CID](/source/S2CID_(identifier)) [14878976](https://api.semanticscholar.org/CorpusID:14878976).

1. **[^](#cite_ref-rgcrv_5-0)** Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", *Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30*, vol. 30, University of Toronto: [International Astronomical Union](/source/International_Astronomical_Union), p. 57, [Bibcode](/source/Bibcode_(identifier)):[1967IAUS...30...57E](https://ui.adsabs.harvard.edu/abs/1967IAUS...30...57E)

1. **[^](#cite_ref-eggen_6-0)** Eggen, O. J. (1984), "The A0 stars", *Astrophysical Journal Supplement Series*, **55**: 597, [Bibcode](/source/Bibcode_(identifier)):[1984ApJS...55..597E](https://ui.adsabs.harvard.edu/abs/1984ApJS...55..597E), [doi](/source/Doi_(identifier)):[10.1086/190971](https://doi.org/10.1086%2F190971).

1. **[^](#cite_ref-Kaler2012_7-0)** [Kaler, James B.](/source/James_B._Kaler) (May 25, 2012), ["Lambda Centauri"](http://stars.astro.illinois.edu/sow/lambdacen.html), *STARS*, retrieved 2021-06-29.

1. ^ [***a***](#cite_ref-mnras189_601_8-0) [***b***](#cite_ref-mnras189_601_8-1) Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", *[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society)*, **189** (3): 601–605, [Bibcode](/source/Bibcode_(identifier)):[1979MNRAS.189..601U](https://ui.adsabs.harvard.edu/abs/1979MNRAS.189..601U), [doi](/source/Doi_(identifier)):[10.1093/mnras/189.3.601](https://doi.org/10.1093%2Fmnras%2F189.3.601).

1. **[^](#cite_ref-mcdonald_9-0)** McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", *Monthly Notices of the Royal Astronomical Society*, **427** (1): 343–357, [arXiv](/source/ArXiv_(identifier)):[1208.2037](https://arxiv.org/abs/1208.2037), [Bibcode](/source/Bibcode_(identifier)):[2012MNRAS.427..343M](https://ui.adsabs.harvard.edu/abs/2012MNRAS.427..343M), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2012.21873.x](https://doi.org/10.1111%2Fj.1365-2966.2012.21873.x), [S2CID](/source/S2CID_(identifier)) [118665352](https://api.semanticscholar.org/CorpusID:118665352).

1. ^ [***a***](#cite_ref-erspamer_10-0) [***b***](#cite_ref-erspamer_10-1) Erspamer, D.; North, P. (2003), "Automated spectroscopic abundances of a and F-type stars using echelle spectrographs. II. Abundances of 140 A-F stars from ELODIE", *Astronomy and Astrophysics*, **398** (3): 1121–1136, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0210065](https://arxiv.org/abs/astro-ph/0210065), [Bibcode](/source/Bibcode_(identifier)):[2003A&A...398.1121E](https://ui.adsabs.harvard.edu/abs/2003A&A...398.1121E), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20021711](https://doi.org/10.1051%2F0004-6361%3A20021711), [S2CID](/source/S2CID_(identifier)) [1109164](https://api.semanticscholar.org/CorpusID:1109164).

1. ^ [***a***](#cite_ref-aaa501_1_297_11-0) [***b***](#cite_ref-aaa501_1_297_11-1) [***c***](#cite_ref-aaa501_1_297_11-2) Zorec, J.; et al. (July 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff", *Astronomy and Astrophysics*, **501** (1): 297–320, [arXiv](/source/ArXiv_(identifier)):[0903.5134](https://arxiv.org/abs/0903.5134), [Bibcode](/source/Bibcode_(identifier)):[2009A&A...501..297Z](https://ui.adsabs.harvard.edu/abs/2009A&A...501..297Z), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/200811147](https://doi.org/10.1051%2F0004-6361%2F200811147), [S2CID](/source/S2CID_(identifier)) [14969137](https://api.semanticscholar.org/CorpusID:14969137).

1. ^ [***a***](#cite_ref-aaa393_897_12-0) [***b***](#cite_ref-aaa393_897_12-1) Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", *Astronomy and Astrophysics*, **393** (3): 897–911, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0205255](https://arxiv.org/abs/astro-ph/0205255), [Bibcode](/source/Bibcode_(identifier)):[2002A&A...393..897R](https://ui.adsabs.harvard.edu/abs/2002A&A...393..897R), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20020943](https://doi.org/10.1051%2F0004-6361%3A20020943), [S2CID](/source/S2CID_(identifier)) [14070763](https://api.semanticscholar.org/CorpusID:14070763).

1. **[^](#cite_ref-SIMBAD_13-0)** ["lam Cen"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=lam+Cen), *[SIMBAD](/source/SIMBAD)*, [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg), retrieved 2021-06-27.

1. **[^](#cite_ref-aaa382_92_14-0)** Shatsky, N.; Tokovinin, A. (January 2002), "The mass ratio distribution of B-type visual binaries in the Sco OB2 association", *Astronomy and Astrophysics*, **382**: 92–103, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0109456](https://arxiv.org/abs/astro-ph/0109456), [Bibcode](/source/Bibcode_(identifier)):[2002A&A...382...92S](https://ui.adsabs.harvard.edu/abs/2002A&A...382...92S), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20011542](https://doi.org/10.1051%2F0004-6361%3A20011542), [S2CID](/source/S2CID_(identifier)) [16697655](https://api.semanticscholar.org/CorpusID:16697655).

1. **[^](#cite_ref-Baume_et_al_2014_15-0)** Baume, G.; et al. (September 2014), "A deep and wide-field view at the IC 2944/2948 complex in Centaurus*", *Monthly Notices of the Royal Astronomical Society*, **443** (1): 411–422, [arXiv](/source/ArXiv_(identifier)):[1406.0708](https://arxiv.org/abs/1406.0708), [Bibcode](/source/Bibcode_(identifier)):[2014MNRAS.443..411B](https://ui.adsabs.harvard.edu/abs/2014MNRAS.443..411B), [doi](/source/Doi_(identifier)):[10.1093/mnras/stu1108](https://doi.org/10.1093%2Fmnras%2Fstu1108).

1. **[^](#cite_ref-omeara2002_16-0)** O'Meara, Stephen James (2002), [*The Caldwell Objects*](https://books.google.com/books?id=3Hg6YHgx9nAC&pg=PA400), [Cambridge University Press](/source/Cambridge_University_Press), pp. 399–400, [ISBN](/source/ISBN_(identifier)) [0-521-82796-5](https://en.wikipedia.org/wiki/Special:BookSources/0-521-82796-5).

1. **[^](#cite_ref-belle2012_17-0)** Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", *The Astronomy and Astrophysics Review*, **20** (1): 51, [arXiv](/source/ArXiv_(identifier)):[1204.2572](https://arxiv.org/abs/1204.2572), [Bibcode](/source/Bibcode_(identifier)):[2012A&ARv..20...51V](https://ui.adsabs.harvard.edu/abs/2012A&ARv..20...51V), [doi](/source/Doi_(identifier)):[10.1007/s00159-012-0051-2](https://doi.org/10.1007%2Fs00159-012-0051-2), [S2CID](/source/S2CID_(identifier)) [119273474](https://api.semanticscholar.org/CorpusID:119273474).

1. **[^](#cite_ref-al33_9_571_18-0)** Bobylev, V. V.; Bajkova, A. T. (September 2007), "Kinematics of the Scorpius–Centaurus OB association", *Astronomy Letters*, **33** (9): 571–583, [arXiv](/source/ArXiv_(identifier)):[0708.0943](https://arxiv.org/abs/0708.0943), [Bibcode](/source/Bibcode_(identifier)):[2007AstL...33..571B](https://ui.adsabs.harvard.edu/abs/2007AstL...33..571B), [doi](/source/Doi_(identifier)):[10.1134/S1063773707090010](https://doi.org/10.1134%2FS1063773707090010), [S2CID](/source/S2CID_(identifier)) [15785349](https://api.semanticscholar.org/CorpusID:15785349).

v t e Constellation of Centaurus List of stars in Centaurus Centaurus in Chinese astronomy Stars Bayer α A (Rigil Kentaurus) B (Toliman) C (Proxima Centauri) β (Hadar) γ δ ε ζ (Leepwal) η θ (Menkent) ι (Kulou) κ λ μ ν (Heng) ξ1 ξ2 ο1 ο2 π ρ σ τ υ1 υ2 φ χ ψ x1 x2 C3 D E F G H J K M N Q Flamsteed 1 (i) 2 (g) 3 (k) 4 (h) Variable R T V Y RR SV SX BV DY UY V346 V553 V744 V752 V761 (a) V763 (C1) V766 V779 (Krzemiński's star) V803 V810 V816 (Przybylski's Star) V831 V842 V885 V886 V863 V1032 V1369 V1400 V1935 HR 4460 (A) 4466 (C2) 4499 4522 4523 4537 (j) 4546 (B) 4721 4748 (u) 4796 4817 (l) 4831 (w) 4874 (p) 4888 (e) 4889 (n) 4940 (f) 4979 4989 5006 (r) 5041 (m) 5089 (d) 5174 (z) 5222 (y) 5224 5241 5297 5358 (v) 5371 5471 (b) 5485 (c1) 5489 (c2) HD 97413 98176 100453 101581 101930 102117 (Uklun) 103197 107914 108236 109749 110113 113538 113766 114386 114729 115600 116434 (Matza) 117207 117618 (Dofida) 117939 120411 121228 121504 124448 (Popper's Star) 125072 125595 131399 Other 2MASS J1126−5003 2M1207 Gaia BH2 HD 131399 Ab PSR B1259−63 PSR J1311−3430 TOI-763 WASP-15 (Nyamien) WASP-41 WASP-42 WASP-167/KELT-13 Exoplanets 2M1207b b Centauri b HD 101930 b HD 102117 b (Leklsullun) HD 103197 b HD 109749 b HD 113538 b c HD 114386 b HD 114729 b HD 117207 b HD 117618 b (Noifasui) HD 121504 b HIP 65426 b (Najsakopajk) HIP 67522 b NGTS-13b Proxima Centauri b c d WASP-15b (Asye) Star clusters NGC 3766 4230 4507 5281 5286 5316 5460 5617 5662 Other IC 2944 ω Centauri Scorpius–Centaurus association Stock 16 Nebulae NGC 3918 5307 Other Boomerang Nebula Fleming 1 G292.0+1.8 G306.3-0.9 Gum 41 IC 2944 IRAS 13208−6020 RCW 79 RCW 86 Southern Crab Nebula SuWt 2 Galaxies NGC 3557 3568 3749 3783 4444 4603 4622 4650A 4683 4696 4706 4709 4729 4730 4743 4744 4909 4930 4945 4976 5011 A 5026 5064 5082 5090 5091 5102 5114 5121 5128 (Centaurus A) 5161 5206 5253 5266 5291 5398 5408 5419 5483 5516 Other ESO 269-57 ESO 325-4 ESO 383-76 ESO 444-46 Fourcade-Figueroa Object IC 3370 IC 4214 IC 4329A IRAS 13224−3809 J1144−4308 LEDA 677373 PKS 1144−379 PKS 1353−341 PKS 1424−418 Galaxy clusters Abell S740 Centaurus Cluster Shapley Supercluster Astronomical events GW190521 SN 185 SN 1895B (Z) SN 1972E SN 1986G J1407b SN 2019so Category

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Adapted from the Wikipedia article [Lambda Centauri](https://en.wikipedia.org/wiki/Lambda_Centauri) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Lambda_Centauri?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.