# Xi2 Centauri

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Xi2_Centauri
> Markdown URL: https://mediated.wiki/source/Xi2_Centauri.md
> Source: https://en.wikipedia.org/wiki/Xi2_Centauri
> Source revision: 1328920596
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Triple star system in the constellation Centaurus

For other stars with this Bayer designation, see [Xi Centauri](/source/Xi_Centauri).

ξ2 Centauri Location of ξ2 Centauri (circled) Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) Constellation Centaurus[1] Right ascension 13h 06m 54.639s[2] Declination −49° 54′ 22.49″[2] Apparent magnitude (V) 4.30[3] + 9.38[4] Characteristics Spectral type B1.5 V[5] or B2 IV[6] + F7 V[4] U−B color index −0.810[3] B−V color index −0.197[3] Astrometry Radial velocity (Rv) +14.3±4.1[7] km/s Proper motion (μ) RA: −27.118 mas/yr[2] Dec.: −12.808 mas/yr[2] Parallax (π) 6.7962±0.1797 mas[2] Distance 480 ± 10 ly (147 ± 4 pc) Absolute magnitude (MV) −1.51[1] Orbit[8] Period (P) 7.6497 d Eccentricity (e) 0.35 Periastron epoch (T) 2418077.493 JD Argument of periastron (ω) (secondary) 308.6° Semi-amplitude (K1) (primary) 38.8 km/s Details ξ2 Cen A Mass 8.1±0.1[5] M☉ Luminosity (bolometric) 1,702[9] L☉ Surface gravity (log g) 4.11±0.03[9] cgs Temperature 20,790±335[9] K Rotational velocity (v sin i) 25[10] km/s Age 11.5±3.7[5] Myr ξ2 Cen B Mass 1.25[9] M☉ Luminosity 2.4[9] L☉ Temperature 6,194[9] K Other designations ξ2 Cen, CD−49°7644, FK5 489, HD 113791, HIP 64004, HR 4942, SAO 223909[11] Database references SIMBAD data

**Xi2 Centauri** is a [triple star](/source/Triple_star)[12] system 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 ξ2 Centauri, and abbreviated Xi2 Cen or ξ2 Cen. This system is visible to the [naked eye](/source/Naked_eye) as a point of light with a combined [apparent visual magnitude](/source/Apparent_visual_magnitude) of 4.30,[3] and forms a wide [optical double](/source/Optical_double) with the slightly dimmer [ξ1 Centauri](/source/Xi1_Centauri).[13] Based upon an annual [parallax shift](/source/Stellar_parallax) of 6.80 [mas](/source/Milliarcsecond), Xi2 Centauri lies roughly 480 [light years](/source/Light_year) from the [Sun](/source/Sun). At that distance, the visual magnitude is diminished by an interstellar [extinction factor](/source/Extinction_(astronomy)) of 0.32 due to intervening dust.[14]

This system was discovered to be a single-lined [spectroscopic binary](/source/Spectroscopic_binary) in 1910 by American astronomer [Joseph Haines Moore](/source/Joseph_Haines_Moore).[15][16] The pair, component A, orbit each other with a [period](/source/Orbital_period) of 7.6497 days and an [eccentricity](/source/Orbital_eccentricity) of 0.35.[8] The primary is a [B-type star](/source/B-type_star) with a [stellar classification](/source/Stellar_classification) of B1.5 V[5] or B2 IV,[6] depending on the source. This indicates it may be a [main sequence star](/source/Main_sequence_star) or a more [evolved](/source/Stellar_evolution) [subgiant star](/source/Subgiant_star). It has about 8.1 times the [mass of the Sun](/source/Solar_mass)[5] and radiates 1,702 times the [solar luminosity](/source/Solar_luminosity) from its [outer atmosphere](/source/Stellar_atmosphere) at an [effective temperature](/source/Effective_temperature) of 20,790 K.[9] It is a [hybrid pulsator](/source/Hybrid_pulsator) and shows variations in both g and p modes.[17]

A third star, component B, is a magnitude 9.38 [F-type main sequence star](/source/F-type_main_sequence_star) with a classification of F7 V. It has 1.25[9] times the mass of the Sun and radiates 2.4[9] times the solar luminosity at an effective temperature of 6,194[9] K. It lies at an [angular separation](/source/Angular_separation) of 25.1 [arc seconds](/source/Arc_second) from the inner pair.[4] They share a [common proper motion](/source/Common_proper_motion), indicating they may be gravitationally bound with an orbital period of around 41,000 years.[18]

The system has a [peculiar velocity](/source/Peculiar_velocity) of 16.2±4.2 km/s.[7] It belongs to the [Scorpius–Centaurus association](/source/Scorpius%E2%80%93Centaurus_association) and appears to be a member of the [Gould's Belt](/source/Gould's_Belt).[19]

## References

1. ^ [***a***](#cite_ref-Anderson2012_1-0) [***b***](#cite_ref-Anderson2012_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=64004&-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-GaiaDR3_2-0) [***b***](#cite_ref-GaiaDR3_2-1) [***c***](#cite_ref-GaiaDR3_2-2) [***d***](#cite_ref-GaiaDR3_2-3) 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%3D6081542475600377472%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-apjs15_459_3-0) [***b***](#cite_ref-apjs15_459_3-1) [***c***](#cite_ref-apjs15_459_3-2) [***d***](#cite_ref-apjs15_459_3-3) Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", *Astrophysical Journal Supplement*, **15**: 459, [Bibcode](/source/Bibcode_(identifier)):[1968ApJS...15..459G](https://ui.adsabs.harvard.edu/abs/1968ApJS...15..459G), [doi](/source/Doi_(identifier)):[10.1086/190168](https://doi.org/10.1086%2F190168).

1. ^ [***a***](#cite_ref-Gahm1983_4-0) [***b***](#cite_ref-Gahm1983_4-1) [***c***](#cite_ref-Gahm1983_4-2) Gahm, G. F.; et al. (January 1983), "A study of visual double stars with early type primaries. I - Spectroscopic results", *Astronomy and Astrophysics Supplement Series*, **51**: 143–159, [Bibcode](/source/Bibcode_(identifier)):[1983A&AS...51..143G](https://ui.adsabs.harvard.edu/abs/1983A&AS...51..143G).

1. ^ [***a***](#cite_ref-Tetzlaff2011_5-0) [***b***](#cite_ref-Tetzlaff2011_5-1) [***c***](#cite_ref-Tetzlaff2011_5-2) [***d***](#cite_ref-Tetzlaff2011_5-3) [***e***](#cite_ref-Tetzlaff2011_5-4) 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](/source/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. ^ [***a***](#cite_ref-Hohle2010_6-0) [***b***](#cite_ref-Hohle2010_6-1) 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-Bobylev2013_7-0) [***b***](#cite_ref-Bobylev2013_7-1) Bobylev, V. V.; Bajkova, A. T. (August 2013), "Galactic kinematics from a sample of young massive stars", *Astronomy Letters*, **39** (8): 532–549, [arXiv](/source/ArXiv_(identifier)):[1307.1677](https://arxiv.org/abs/1307.1677), [Bibcode](/source/Bibcode_(identifier)):[2013AstL...39..532B](https://ui.adsabs.harvard.edu/abs/2013AstL...39..532B), [doi](/source/Doi_(identifier)):[10.1134/S106377371308001X](https://doi.org/10.1134%2FS106377371308001X), [S2CID](/source/S2CID_(identifier)) [118568203](https://api.semanticscholar.org/CorpusID:118568203).

1. ^ [***a***](#cite_ref-Pourbaix2004_8-0) [***b***](#cite_ref-Pourbaix2004_8-1) Pourbaix, D.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", *Astronomy & Astrophysics*, **424** (2): 727–732, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0406573](https://arxiv.org/abs/astro-ph/0406573), [Bibcode](/source/Bibcode_(identifier)):[2004A&A...424..727P](https://ui.adsabs.harvard.edu/abs/2004A&A...424..727P), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20041213](https://doi.org/10.1051%2F0004-6361%3A20041213), [S2CID](/source/S2CID_(identifier)) [119387088](https://api.semanticscholar.org/CorpusID:119387088).

1. ^ [***a***](#cite_ref-Gerbaldi2001_9-0) [***b***](#cite_ref-Gerbaldi2001_9-1) [***c***](#cite_ref-Gerbaldi2001_9-2) [***d***](#cite_ref-Gerbaldi2001_9-3) [***e***](#cite_ref-Gerbaldi2001_9-4) [***f***](#cite_ref-Gerbaldi2001_9-5) [***g***](#cite_ref-Gerbaldi2001_9-6) [***h***](#cite_ref-Gerbaldi2001_9-7) [***i***](#cite_ref-Gerbaldi2001_9-8) [***j***](#cite_ref-Gerbaldi2001_9-9) Gerbaldi, M.; et al. (November 2001), "Binary systems with post-T Tauri secondaries", *Astronomy and Astrophysics*, **379**: 162–184, [Bibcode](/source/Bibcode_(identifier)):[2001A&A...379..162G](https://ui.adsabs.harvard.edu/abs/2001A&A...379..162G), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20011298](https://doi.org/10.1051%2F0004-6361%3A20011298).

1. **[^](#cite_ref-Wolff2007_10-0)** Wolff, S. C.; et al. (2007), "Rotational Velocities for B0-B3 Stars in Seven Young Clusters: Further Study of the Relationship between Rotation Speed and Density in Star-Forming Regions", *[The Astronomical Journal](/source/The_Astronomical_Journal)*, **133** (3): 1092–1103, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0702133](https://arxiv.org/abs/astro-ph/0702133), [Bibcode](/source/Bibcode_(identifier)):[2007AJ....133.1092W](https://ui.adsabs.harvard.edu/abs/2007AJ....133.1092W), [doi](/source/Doi_(identifier)):[10.1086/511002](https://doi.org/10.1086%2F511002), [S2CID](/source/S2CID_(identifier)) [119074863](https://api.semanticscholar.org/CorpusID:119074863).

1. **[^](#cite_ref-SIMBAD_11-0)** ["ksi02 Cen"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ksi02+Cen), *[SIMBAD](/source/SIMBAD)*, [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg), retrieved 2017-01-09.

1. **[^](#cite_ref-Eggleton2008_12-0)** Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", *[Monthly Notices of the Royal Astronomical Society](/source/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-FogCity2003_13-0)** [*Backyard Astronomy*](https://books.google.com/books?id=QWynWiw_4i8C), The Guides, Fog City Press, 2003, p. 248, [ISBN](/source/ISBN_(identifier)) [1877019321](https://en.wikipedia.org/wiki/Special:BookSources/1877019321).

1. **[^](#cite_ref-Gontcharov2012_14-0)** Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", *Astronomy Letters*, **38** (11): 694–706, [arXiv](/source/ArXiv_(identifier)):[1606.09028](https://arxiv.org/abs/1606.09028), [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..694G](https://ui.adsabs.harvard.edu/abs/2012AstL...38..694G), [doi](/source/Doi_(identifier)):[10.1134/S1063773712110035](https://doi.org/10.1134%2FS1063773712110035), [S2CID](/source/S2CID_(identifier)) [119108982](https://api.semanticscholar.org/CorpusID:119108982).

1. **[^](#cite_ref-Moore1910_15-0)** Moore, Joseph Haines (1910), "Ten stars having variable radial velocities", *Lick Observatory Bulletin*, **6** (182): 55–59, [Bibcode](/source/Bibcode_(identifier)):[1910LicOB...6...55M](https://ui.adsabs.harvard.edu/abs/1910LicOB...6...55M), [doi](/source/Doi_(identifier)):[10.5479/ADS/bib/1910LicOB.6.55M](https://doi.org/10.5479%2FADS%2Fbib%2F1910LicOB.6.55M).

1. **[^](#cite_ref-Meubauer1931_16-0)** Neubauer, F. J. (1931), "The orbit of the spectroscopic binary ξ2 Centauri", *Lick Observatory Bulletin*, **15**: 107–108, [Bibcode](/source/Bibcode_(identifier)):[1931LicOB..15..107N](https://ui.adsabs.harvard.edu/abs/1931LicOB..15..107N), [doi](/source/Doi_(identifier)):[10.5479/ADS/bib/1931LicOB.15.107N](https://doi.org/10.5479%2FADS%2Fbib%2F1931LicOB.15.107N).

1. **[^](#cite_ref-Sharma_17-0)** Sharma, Awshesh N.; et al. (2022), "Pulsating B stars in the Scorpius–Centaurus Association with TESS", *Monthly Notices of the Royal Astronomical Society*, **515** (1): 828–840, [arXiv](/source/ArXiv_(identifier)):[2203.02582](https://arxiv.org/abs/2203.02582), [Bibcode](/source/Bibcode_(identifier)):[2022MNRAS.515..828S](https://ui.adsabs.harvard.edu/abs/2022MNRAS.515..828S), [doi](/source/Doi_(identifier)):[10.1093/mnras/stac1816](https://doi.org/10.1093%2Fmnras%2Fstac1816).

1. **[^](#cite_ref-Tokovinin2008_18-0)** Tokovinin, A. (September 2008), "Comparative statistics and origin of triple and quadruple stars", *Monthly Notices of the Royal Astronomical Society*, **389** (2): 925–938, [arXiv](/source/ArXiv_(identifier)):[0806.3263](https://arxiv.org/abs/0806.3263), [Bibcode](/source/Bibcode_(identifier)):[2008MNRAS.389..925T](https://ui.adsabs.harvard.edu/abs/2008MNRAS.389..925T), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2008.13613.x](https://doi.org/10.1111%2Fj.1365-2966.2008.13613.x), [S2CID](/source/S2CID_(identifier)) [16452670](https://api.semanticscholar.org/CorpusID:16452670).

1. **[^](#cite_ref-Bobylev2007_19-0)** 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).

## External links

- [http://server3.wikisky.org/starview?object_type=1&object_id=884](http://server3.wikisky.org/starview?object_type=1&object_id=884)

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

---
Adapted from the Wikipedia article [Xi2 Centauri](https://en.wikipedia.org/wiki/Xi2_Centauri) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Xi2_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.