R Centauri
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 14h 16m 34.321s[1] |
| Declination | −59° 54′ 49.29″[1] |
| Apparent magnitude (V) | 5.2 - 11.5[2] |
| Characteristics | |
| Spectral type | M5IIe[3] (M4e-M9.5[2]) |
| U−B color index | +1.24[4] |
| B−V color index | +2.04[4] |
| Variable type | Mira[2] |
| Astrometry | |
| Radial velocity (Rv) | −19.8[5] km/s |
| Proper motion (μ) | RA: -9.07 ± 0.91[1] mas/yr Dec.: -7.04 ± 0.71[1] mas/yr |
| Parallax (π) | 2.60 ± 0.76 mas[1] |
| Distance | approx. 1,300 ly (approx. 400 pc) |
| Absolute magnitude (MV) | −1.49 (at maximum)[6] |
| Details | |
| Luminosity | 47,000[3] L☉ |
| Temperature | 3,450[3] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
R Centauri (R Cen) is a Mira variable star in the constellation Centaurus. It is approximately 1,300 light years from Earth.
R Centauri is a Mira variable and its brightness varies from magnitude +5.2 to +11.5 with a period of about 500 days. It used to have an unusual double-peaked light curve, but by 2001 this had reverted to an almost normal single-peaked curve. Prior to 1950 the period was about 550 days, but since then has decreased to about 500 days. A 2016 analysis of ASAS data derived a period of 498.84 days.[7]
It is thought that the unusual behaviour of R Centauri is caused by a flash in the helium shell around its core, which occurs periodically in asymptotic giant branch (AGB) stars as the mass of the helium shell increases with helium from the outer hydrogen shell.[8]
It is also an H2O maser source.[9]
References
- ^ a b c d e 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. Vizier catalog entry
- ^ a b c 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. Bibcode:2009yCat....102025S.
- ^ a b c Verhoelst, T; Van Der Zypen, N; Hony, S; Decin, L; Cami, J; Eriksson, K (2009). "The dust condensation sequence in red supergiant stars". Astronomy & Astrophysics. 498 (1): 127–138. arXiv:0901.1262. Bibcode:2009A&A...498..127V. doi:10.1051/0004-6361/20079063.
- ^ a b Hoffleit, Dorrit; Jaschek, Carlos (1991). "The Bright star catalogue". New Haven. Bibcode:1991bsc..book.....H.
- ^ Wilson, R.E (1953). General Catalogue of Stellar Radial Velocities. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
- ^ Celis s, L. (1986). "Spectral and luminosity variation of long-period red variable stars". The Astronomical Journal. 91: 405. Bibcode:1986AJ.....91..405C. doi:10.1086/114019.
- ^ Vogt, N; Contreras-Quijada, A; Fuentes-Morales, I; Vogt-Geisse, S; Arcos, C; Abarca, C; Agurto-Gangas, C; Caviedes, M; Dasilva, H; Flores, J; Gotta, V; Peñaloza, F; Rojas, K; Villaseñor, J. I (2016). "Determination of Pulsation Periods and Other Parameters of 2875 Stars Classified As Mira in the All Sky Automated Survey (Asas)". The Astrophysical Journal Supplement Series. 227 (1): 6. arXiv:1609.05246. Bibcode:2016ApJS..227....6V. doi:10.3847/0067-0049/227/1/6.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Hawkins, G; Mattei, J. A; Foster, G (2001). "R Centauri: An Unusual Mira Variable in a He‐Shell Flash". Publications of the Astronomical Society of the Pacific. 113 (782): 501. Bibcode:2001PASP..113..501H. doi:10.1086/319542.
- ^ Lepine, J.R.D.; Paes de Barros, M.H. (1977). "Characteristics of the H2O emission from Mira variables". Astronomy and Astrophysics. 56: 219–226. Bibcode:1977A&A....56..219L.
