# Epsilon Centauri

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Star in the constellation Centaurus

This article is about ε Centauri; not to be confused with [E Centauri](/source/E_Centauri) or [e Centauri](/source/HD_111915).

ε Centauri Location of ε Centauri (circled) Observation data Epoch J2000 Equinox J2000 Constellation Centaurus[1] Right ascension 13h 39m 53.25774s[2] Declination −53° 27′ 59.0081″[2] Apparent magnitude (V) 2.29 - 2.31[3] Characteristics Spectral type B1 III[4] U−B color index −0.92[5] B−V color index −0.22[5] Variable type β Cep[3] Astrometry Radial velocity (Rv) +3.0[6] km/s Proper motion (μ) RA: −15.30[2] mas/yr Dec.: −11.72[2] mas/yr Parallax (π) 7.63±0.48 mas[2] Distance 430 ± 30 ly (131 ± 8 pc) Absolute magnitude (MV) −3.29[1] Details Mass 8.2[7] M☉ Radius 5.8[8] R☉ Luminosity 16,137[8] L☉ Surface gravity (log g) 3.88[8] cgs Temperature 24,937[8] K Metallicity [Fe/H] −0.14±0.10[9] dex Rotational velocity (v sin i) 140[10] km/s Age 16.3[11] Myr Other designations ε Cen, CPD−52°6655, FK5 504, HD 118716, HIP 66657, HR 5132, SAO 241047[12] Database references SIMBAD data

**Epsilon Centauri** is a [star](/source/Star) in the southern [constellation](/source/Constellation) of [Centaurus](/source/Centaurus). Its name is a [Bayer designation](/source/Bayer_designation) that is [Latinized](/source/Romanization_of_Greek) from ε Centauri, and abbreviated Epsilon Cen or ε Cen. This is one of the [brightest stars](/source/List_of_stars_in_Centaurus) in the constellation with a slightly variable [apparent visual magnitude](/source/Apparent_visual_magnitude) of +2.30. [Parallax](/source/Parallax) measurements put it at a distance of around 430 [light-years](/source/Light-year) (130 [parsecs](/source/Parsec)) from [Earth](/source/Earth).

In [Chinese](/source/Chinese_astronomy), 南門 (*Nán Mén*), meaning *[Southern Gate](/source/Horn_(Chinese_constellation))*, refers to an asterism consisting of ε Centauri and [α Centauri](/source/Alpha_Centauri).[13] Consequently, the [Chinese name](/source/Chinese_star_names) for ε Centauri itself is 南門一 (*Nán Mén yī*, English: the First Star of Southern Gate.)[14]

A yellow-light [light curve](/source/Light_curve) for Epsilon Centauri, adapted from Shobbrook (1972)[15]

ε Centauri is a massive star with 8.2 times the [mass of the Sun](/source/Mass_of_the_Sun).[7] The [spectrum](/source/Stellar_spectrum) matches a [stellar classification](/source/Stellar_classification) of B1 III,[4] indicating this is an [evolved](/source/Stellar_evolution) [giant star](/source/Giant_star). It is radiating more than 16,000 times the [luminosity of the Sun](/source/Luminosity_of_the_Sun)[8] from its outer atmosphere at an [effective temperature](/source/Effective_temperature) of about 25,000 [K](/source/Kelvin),[8] giving it the blue-white hue of a B-type star.[16] It is classified as a [Beta Cephei type](/source/Beta_Cephei_variable) [variable star](/source/Variable_star) with a primary period of 0.16961 days (4 hours 4 minutes), completing 5.9 cycles per day.[9] During each cycle, the brightness of the star varies from apparent magnitude +2.29 to +2.31.

This star is a [proper motion](/source/Proper_motion) member of the Lower Centaurus–Crux sub-group in the [Scorpius–Centaurus](/source/Scorpius%E2%80%93Centaurus_association) [OB association](/source/Stellar_association), the nearest such association of co-moving massive stars to the Sun.[17] Epsilon Centauri is a relatively young star, with an age of around 16 million years.[18]

The [IAU](/source/IAU) has not assigned a proper name to this star.[19]

## References

1. ^ [***a***](#cite_ref-xhip_1-0) [***b***](#cite_ref-xhip_1-1) Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". *[Astronomy Letters](/source/Astronomy_Letters)*. **38** (5): 331. [arXiv](/source/ArXiv_(identifier)):[1108.4971](https://arxiv.org/abs/1108.4971). [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..331A](https://ui.adsabs.harvard.edu/abs/2012AstL...38..331A). [doi](/source/Doi_(identifier)):[10.1134/S1063773712050015](https://doi.org/10.1134%2FS1063773712050015). [XHIP record for this object](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-ref=VIZ681510a8389ecb&-out.src=V%2F137D%2FXHIP&-nav=cat%3AV%2F137D%26tab%3A{V%2F137D%2FXHIP}%26key%3Asource%3DV%2F137D%2FXHIP%26HTTPPRM%3A&-source=V%2F137D%2FXHIP&-out=HIP&HIP=66657&-out=Comp&-out=Gr&-out=RAJ2000&-out=DEJ2000&-out=Dist&-out=X&-out=Y&-out=Z&-out=SpType&-out=Simbad&-out=Hpmag&-out=Lum&-out=Cst) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-aaa474_2_653_2-0) [***b***](#cite_ref-aaa474_2_653_2-1) [***c***](#cite_ref-aaa474_2_653_2-2) [***d***](#cite_ref-aaa474_2_653_2-3) [***e***](#cite_ref-aaa474_2_653_2-4) van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". *Astronomy and Astrophysics*. **474** (2): 653–664. [arXiv](/source/ArXiv_(identifier)):[0708.1752](https://arxiv.org/abs/0708.1752). [Bibcode](/source/Bibcode_(identifier)):[2007A&A...474..653V](https://ui.adsabs.harvard.edu/abs/2007A&A...474..653V). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20078357](https://doi.org/10.1051%2F0004-6361%3A20078357). [S2CID](/source/S2CID_(identifier)) [18759600](https://api.semanticscholar.org/CorpusID:18759600).

1. ^ [***a***](#cite_ref-gcvs_3-0) [***b***](#cite_ref-gcvs_3-1) Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". *VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S*. **1**: 02025. [Bibcode](/source/Bibcode_(identifier)):[2009yCat....102025S](https://ui.adsabs.harvard.edu/abs/2009yCat....102025S).

1. ^ [***a***](#cite_ref-an331_4_349_4-0) [***b***](#cite_ref-an331_4_349_4-1) Hohle, M. M.; et al. (April 2010). "Masses and luminosities of O- and B-type stars and red supergiants". *Astronomische Nachrichten*. **331** (4): 349. [arXiv](/source/ArXiv_(identifier)):[1003.2335](https://arxiv.org/abs/1003.2335). [Bibcode](/source/Bibcode_(identifier)):[2010AN....331..349H](https://ui.adsabs.harvard.edu/abs/2010AN....331..349H). [doi](/source/Doi_(identifier)):[10.1002/asna.200911355](https://doi.org/10.1002%2Fasna.200911355). [S2CID](/source/S2CID_(identifier)) [111387483](https://api.semanticscholar.org/CorpusID:111387483).

1. ^ [***a***](#cite_ref-ducati_5-0) [***b***](#cite_ref-ducati_5-1) Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". *CDS/ADC Collection of Electronic Catalogues*. **2237**: 0. [Bibcode](/source/Bibcode_(identifier)):[2002yCat.2237....0D](https://ui.adsabs.harvard.edu/abs/2002yCat.2237....0D).

1. **[^](#cite_ref-rgcrv_6-0)** Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). *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. ^ [***a***](#cite_ref-quintana2025_7-0) [***b***](#cite_ref-quintana2025_7-1) Quintana, Alexis L.; Wright, Nicholas J.; Martínez García, Juan (2025). ["A census of OB stars within 1 KPC and the star formation and core collapse supernova rates of the Milky Way"](https://doi.org/10.1093%2Fmnras%2Fstaf083). *Monthly Notices of the Royal Astronomical Society*. **538** (3): 1367. [arXiv](/source/ArXiv_(identifier)):[2503.08286](https://arxiv.org/abs/2503.08286). [Bibcode](/source/Bibcode_(identifier)):[2025MNRAS.538.1367Q](https://ui.adsabs.harvard.edu/abs/2025MNRAS.538.1367Q). [doi](/source/Doi_(identifier)):[10.1093/mnras/staf083](https://doi.org/10.1093%2Fmnras%2Fstaf083).

1. ^ [***a***](#cite_ref-mcdonald2017_8-0) [***b***](#cite_ref-mcdonald2017_8-1) [***c***](#cite_ref-mcdonald2017_8-2) [***d***](#cite_ref-mcdonald2017_8-3) [***e***](#cite_ref-mcdonald2017_8-4) [***f***](#cite_ref-mcdonald2017_8-5) McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). ["Fundamental parameters and infrared excesses of Tycho-Gaia stars"](https://doi.org/10.1093%2Fmnras%2Fstx1433). *Monthly Notices of the Royal Astronomical Society*. **471** (1): 770. [arXiv](/source/ArXiv_(identifier)):[1706.02208](https://arxiv.org/abs/1706.02208). [Bibcode](/source/Bibcode_(identifier)):[2017MNRAS.471..770M](https://ui.adsabs.harvard.edu/abs/2017MNRAS.471..770M). [doi](/source/Doi_(identifier)):[10.1093/mnras/stx1433](https://doi.org/10.1093%2Fmnras%2Fstx1433).

1. ^ [***a***](#cite_ref-aaa433_3_1031_9-0) [***b***](#cite_ref-aaa433_3_1031_9-1) Daszyńska-Daszkiewicz, J.; Niemczura, E. (April 2005). "Metallicity of mono- and multiperiodic β Cephei stars". *Astronomy and Astrophysics*. **433** (3): 1031–1035. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0410442](https://arxiv.org/abs/astro-ph/0410442). [Bibcode](/source/Bibcode_(identifier)):[2005A&A...433.1031D](https://ui.adsabs.harvard.edu/abs/2005A&A...433.1031D). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20040397](https://doi.org/10.1051%2F0004-6361%3A20040397). [S2CID](/source/S2CID_(identifier)) [119340011](https://api.semanticscholar.org/CorpusID:119340011).

1. **[^](#cite_ref-vanbelle2012_10-0)** Van Belle, Gerard T. (2012). "Interferometric observations of rapidly rotating stars". *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).

1. **[^](#cite_ref-gratton2023_11-0)** Gratton, R.; Squicciarini, V.; Nascimbeni, V.; Janson, M.; Reffert, S.; Meyer, M.; Delorme, P.; Mamajek, E. E.; Bonavita, M.; Desidera, S.; Mesa, D.; Rigliaco, E.; d'Orazi, V.; Vigan, A.; Lazzoni, C.; Chauvin, G.; Langlois, M. (2023). "Multiples among B stars in the Scorpius-Centaurus association". *Astronomy and Astrophysics*. **678**: A93. [arXiv](/source/ArXiv_(identifier)):[2308.09962](https://arxiv.org/abs/2308.09962). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...678A..93G](https://ui.adsabs.harvard.edu/abs/2023A&A...678A..93G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202346806](https://doi.org/10.1051%2F0004-6361%2F202346806).

1. **[^](#cite_ref-SIMBAD_12-0)** ["Eps Cen"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Eps+Cen). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2025-12-08.

1. **[^](#cite_ref-zh_13-0)** (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](/source/ISBN_(identifier)) [978-986-7332-25-7](https://en.wikipedia.org/wiki/Special:BookSources/978-986-7332-25-7).

1. **[^](#cite_ref-AEEA_14-0)** (in Chinese) [AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 25 日](http://aeea.nmns.edu.tw/2006/0607/ap060725.html) [Archived](https://web.archive.org/web/20110522124501/http://aeea.nmns.edu.tw/2006/0607/ap060725.html) 2011-05-22 at the [Wayback Machine](/source/Wayback_Machine)

1. **[^](#cite_ref-Shobbrook_15-0)** Shobbrook, R. R. (1972). ["Two new Beta Canis Majoris variables: epsilon Cen and delta Lup"](https://doi.org/10.1093%2Fmnras%2F157.1.5P). *Monthly Notices of the Royal Astronomical Society*. **157**. [Bibcode](/source/Bibcode_(identifier)):[1972MNRAS.157P...5S](https://ui.adsabs.harvard.edu/abs/1972MNRAS.157P...5S). [doi](/source/Doi_(identifier)):[10.1093/mnras/157.1.5P](https://doi.org/10.1093%2Fmnras%2F157.1.5P).

1. **[^](#cite_ref-csiro_16-0)** ["The Colour of Stars"](https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html). *Australia Telescope, Outreach and Education*. [Commonwealth Scientific and Industrial Research Organisation](/source/Commonwealth_Scientific_and_Industrial_Research_Organisation). December 21, 2004. Archived from [the original](http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html) on 2012-03-18. Retrieved 2012-01-16.

1. **[^](#cite_ref-aaa216_1_44_17-0)** de Geus, E. J.; et al. (June 1989). "Physical parameters of stars in the Scorpio-Centaurus OB association". *Astronomy and Astrophysics*. **216** (1–2): 44–61. [Bibcode](/source/Bibcode_(identifier)):[1989A&A...216...44D](https://ui.adsabs.harvard.edu/abs/1989A&A...216...44D).

1. **[^](#cite_ref-mnras410_1_190_18-0)** Tetzlaff, N.; et al. (January 2011). ["A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun"](https://doi.org/10.1111%2Fj.1365-2966.2010.17434.x). *Monthly Notices of the Royal Astronomical Society*. **410** (1): 190–200. [arXiv](/source/ArXiv_(identifier)):[1007.4883](https://arxiv.org/abs/1007.4883). [Bibcode](/source/Bibcode_(identifier)):[2011MNRAS.410..190T](https://ui.adsabs.harvard.edu/abs/2011MNRAS.410..190T). [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2010.17434.x](https://doi.org/10.1111%2Fj.1365-2966.2010.17434.x). [S2CID](/source/S2CID_(identifier)) [118629873](https://api.semanticscholar.org/CorpusID:118629873).

1. **[^](#cite_ref-iau_19-0)** ["Naming Stars"](https://web.archive.org/web/20250310063743/https://www.iau.org/public/themes/naming_stars/). [International Astronomical Union](/source/International_Astronomical_Union). Archived from [the original](https://www.iau.org/public/themes/naming_stars/) on 2025-03-10. Retrieved 2023-09-14.

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 [Epsilon Centauri](https://en.wikipedia.org/wiki/Epsilon_Centauri) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Epsilon_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.