| A | B |
|---|---|
Alpha Centauri AB (left) forms a triple star system with Proxima Centauri (below, south of, α Centauri AB). (See labelled version) | … |
| Observation data Epoch J2000.0 Equinox ICRS | … |
| Constellation | Centaurus |
| **α Centauri A (Rigil Kentaurus) ** | … |
| Right ascension | 14 39 36.494001 |
| Declination | −60° 50′ 02.3737″1 |
| Apparent magnitude (V) | +0.012 |
| **α Centauri B (Toliman) ** | … |
| Right ascension | 14 39 35.063111 |
| Declination | −60° 50′ 15.0992″1 |
| Apparent magnitude (V) | +1.332 |
| Characteristics | … |
| A | … |
| Spectral type | G2V3 |
| B−V colour index | +0.712 |
| B | … |
| Spectral type | K1V3 |
| B−V colour index | +0.882 |
| Astrometry | … |
| A | … |
| Radial velocity (R) | −21.4±0.764 km/s |
| Proper motion (μ) | RA: −3679.251 mas/yr Dec.: +473.671 mas/yr |
| Parallax (π) | 750.81±0.38 mas5 |
| Distance | 4.344 ± 0.002 ly (1.3319 ± 0.0007 pc) |
| Absolute magnitude (M) | 4.386 |
| B | … |
| Radial velocity (R) | −18.6±1.644 km/s |
| Proper motion (μ) | RA: −3614.391 mas/yr Dec.: +802.981 mas/yr |
| Parallax (π) | 750.81±0.38 mas5 |
| Distance | 4.344 ± 0.002 ly (1.3319 ± 0.0007 pc) |
| Absolute magnitude (M) | 5.716 |
| Orbit 5 | … |
| Primary | A |
| Name | B |
| Period (P) | 79.762±0.019 yr |
| Semi-major axis (a) | 17.493±0.0096” (23.299 AU7) |
| Eccentricity (e) | 0.51947±0.00015 |
| Inclination (i) | 79.243±0.0089° |
| Longitude of the node (Ω) | 205.073±0.025° |
| Periastron epoch (T) | 1875.66±0.012 |
| Argument of periastron (ω) (secondary) | 231.519±0.027° |
| Details | … |
| α Centauri A | … |
| Mass | 1.0788±0.00295 M |
| Radius | 1.2175±0.00555 R |
| Luminosity | 1.5059±0.00195 L |
| Surface gravity (log g) | 4.308 cgs |
| Temperature | 5,804±139 K |
| Metallicity [Fe/H] | 0.20±0.019 dex |
| Rotation | 28.3±0.5 d10 |
| Rotational velocity (v sin i) | 2.7±0.711 km/s |
| Age | 7.2–7.812 Gyr |
| α Centauri B | … |
| Mass | 0.9092±0.00255 M |
| Radius | 0.8591±0.00365 R |
| Luminosity | 0.4981±0.00075 L |
| Surface gravity (log g) | 4.378 cgs |
| Temperature | 5,207±129 K |
| Metallicity [Fe/H] | 0.24±0.019 dex |
| Rotation | 36.7±0.3 d13 |
| Rotational velocity (v sin i) | 1.1±0.814 km/s |
| Age | 7.2–7.812 Gyr |
| Other designations | … |
| α Cen, CD−60°5293, CPD−60°5483, FK5 538, GC 19728, GJ 559, SAO 252838, CCDM J14396-6050 | … |
| α Cen A: Rigil Kentaurus, Rigil Kent, α Cen, HD 128620, HIP 71683, HR 5459, LHS 50, PLX 3309 | … |
| α Cen B: Toliman, α Cen, HD 128621, HIP 71681, HR 5460, LHS 51 | … |
| Database references | … |
| SIMBAD | AB |
| A | |
| B | |
| Exoplanet Archive | data |
| ARICNS | data |
Alpha Centauri AB15
(echo:: @ ᯤ)
Footnotes
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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 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8
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Ducati, J. R. (2002). Catalogue of Stellar Photometry in Johnson’s 11 color system. VizieR Online Data Catalog (Report). CDS/ADC Collection of Electronic Catalogues. Vol. 2237. Bibcode:2002yCat.2237…0D. ↩ ↩2 ↩3 ↩4
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Torres, C.A.O.; Quast, G.R.; da Silva, L.; de la Reza, R.; Melo, C.H.F.; Sterzik, M. (2006). “Search for associations containing young stars (SACY)”. Astronomy and Astrophysics. 460 (3): 695–708. arXiv:astro-ph/0609258. Bibcode:2006A&A…460..695T. doi:10.1051/0004-6361:20065602. ISSN 0004-6361. S2CID 16080025. ↩ ↩2
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Valenti, Jeff A.; Fischer, Debra A. (2005). “Spectroscopic properties of cool stars (SPOCS) I. 1040 F, G, and K dwarfs from Keck, Lick, and AAT planet search programs”. The Astrophysical Journal Supplement Series. 159 (1): 141–166. Bibcode:2005ApJS..159..141V. doi:10.1086/430500. ISSN 0067-0049. ↩ ↩2
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Akeson, Rachel; Beichman, Charles; Kervella, Pierre; Fomalont, Edward; Benedict, G. Fritz (20 April 2021). “Precision millimeter astrometry of the α Centauri AB system”. The Astronomical Journal. 162 (1): 14. arXiv:2104.10086. Bibcode:2021AJ…162…14A. doi:10.3847/1538-3881/abfaff. S2CID 233307418. ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9
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Wiegert, P.A.; Holman, M.J. (1997). “The stability of planets in the Alpha Centauri system”. The Astronomical Journal. 113: 1445–1450. arXiv:astro-ph/9609106. Bibcode:1997AJ…113.1445W. doi:10.1086/118360. S2CID 18969130. ↩ ↩2
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Semi-major axis in AU = semimajor axis in seconds/parallax = 17.493″/0.75081 = 23.299 AU; as the eccentricity is 0.52, the distance fluctuates between 48% and 152% of that, roughly from 11 AU to 35 AU. ↩
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Gilli, G.; Israelian, G.; Ecuvillon, A.; Santos, N.C.; Mayor, M. (2006). “Abundances of refractory elements in the atmospheres of stars with extrasolar planets”. Astronomy and Astrophysics. 449 (2): 723–736. arXiv:astro-ph/0512219. Bibcode:2006A&A…449..723G. doi:10.1051/0004-6361:20053850. S2CID 13039037. libcode 2005astro.ph.12219G. ↩ ↩2
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Soubiran, C.; Creevey, O. L.; Lagarde, N.; Brouillet, N.; Jofré, P.; Casamiquela, L.; Heiter, U.; Aguilera-Gómez, C.; Vitali, S.; Worley, C.; de Brito Silva, D. (1 February 2024). “Gaia FGK benchmark stars: Fundamental Teff and log g of the third version”. Astronomy and Astrophysics. 682: A145. arXiv:2310.11302. Bibcode:2024A&A…682A.145S. doi:10.1051/0004-6361/202347136. ISSN 0004-6361. Alpha Centauri’s database entry at VizieR. ↩ ↩2 ↩3 ↩4
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Huber, Daniel; Zwintz, Konstanze; et al. (the BRITE team) (July 2020). “Solar-like oscillations: Lessons learned & first results from TESS”. Stars and Their Variability Observed from Space: 457. arXiv:2007.02170. Bibcode:2020svos.conf..457H. ↩
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Bazot, M.; et al. (2007). “Asteroseismology of α Centauri A. Evidence of rotational splitting”. Astronomy and Astrophysics. 470 (1): 295–302. arXiv:0706.1682. Bibcode:2007A&A…470..295B. doi:10.1051/0004-6361:20065694. S2CID 118785894. ↩
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Thévenin, F.; Baturin, V. A.; Oreshina, A. V.; Morel, P.; Ayukov, S. V.; Bigot, L.; Gorshkov, A. B. (2026). “A mapping method of age estimation for binary stars: Application to the α Centauri system A and B”. Astronomy & Astrophysics. 707: A353. arXiv:2602.08879. Bibcode:2026A&A…707A.353T. doi:10.1051/0004-6361/202558384. ↩ ↩2
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Dumusque, Xavier (December 2014). “Deriving Stellar Inclination of Slow Rotators Using Stellar Activity”. The Astrophysical Journal. 796 (2): 133. arXiv:1409.3593. Bibcode:2014ApJ…796..133D. doi:10.1088/0004-637X/796/2/133. S2CID 119184190. ↩
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Raassen, A.J.J.; Ness, J.-U.; Mewe, R.; van der Meer, R.L.J.; Burwitz, V.; Kaastran, J.S. (2003). “Chandra-LETGS X-ray observation of α Centauri: A nearby (G2V + K1V) binary system”. Astronomy & Astrophysics. 400 (2): 671–678. Bibcode:2003A&A…400..671R. doi:10.1051/0004-6361:20021899. ↩
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Proxima Centauri is gravitationally bound to the α Centauri system, but for practical and historical reasons it is described in detail in its own article. ↩