RT Carinae
RT Carinae is the bright orange star south of the Trumpler 15 cluster. | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina[1] |
| Right ascension | 10h 44m 47.148s[2] |
| Declination | −59° 24′ 48.1228″[2] |
| Apparent magnitude (V) | 8.2 - 9.9[3] |
| Characteristics | |
| Spectral type | M2+ Iab[4] |
| B−V color index | +2.31[5] |
| Variable type | LC[3] |
| Astrometry | |
| Radial velocity (Rv) | −21.95±0.58[2] km/s |
| Proper motion (μ) | RA: −7.432 mas/yr[2] Dec.: +2.851 mas/yr[2] |
| Parallax (π) | 0.470±0.069 mas[6] |
| Distance | approx. 7,000 ly (approx. 2,100 pc) |
| Absolute magnitude (MV) | −6.74[5] |
| Details[5] | |
| Radius | 1,090 R☉ |
| Luminosity (bolometric) | 129,000+33,000 −24,000[7] L☉ |
| Surface gravity (log g) | −0.3 cgs |
| Temperature | 3,625 K |
| Other designations | |
| RT Car, HD 303310, HIP 52562, SAO 238424, CD−58°3538, AAVSO 1040-58 | |
| Database references | |
| SIMBAD | data |
RT Carinae (CD−58 3538) is a red supergiant or hypergiant[3] variable star, located 7,000 light years away in the constellation Carina and in the Carina Nebula. The apparent magnitude varying around +9 is too faint to be visible to the naked eye.
Observational history
In 1898 it was announced that Louisa D. Wells had discovered that the star's brightness varies. The initial variable star designation given was R Carinae, but that name was eventually given to a different star.[9] It appears with its current name, RT Carinae, in Annie Jump Cannon's 1907 work, Second Catalogue of Variable Stars.[10] It is catalogued as an irregular variable star, but a number of possible pulsation periods have been detected. Analysis from observations over 40 years give variations with periods of 201 and 448 days, with other studies suggesting periods of 100 and 1,400 days.[11]
Characteristics
RT Carinae is a red supergiant with a spectral type given in the General Catalogue of Variable Stars as M2Ia-0,[3] suggesting the star is a hypergiant or an extremely luminous supergiant. It has been defined as a standard star for the MK spectral classification of M2+ Iab,[4] which suggests the star to be an intermediate-luminosity supergiant.
The star has a temperature of 3,625 K and a radius about 1,090 times that of the Sun,[5] with an estimated luminosity 130,000 times that of the Sun.[7] It is close to the open cluster Trumpler 15, but is not thought to be a member.[12] It appears to be surrounded by a dusty nebula, possibly material ejected from the star itself.[13]
References
- ^ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d 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 Keenan, P.; McNeil, R. (October 1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245–266. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. S2CID 123149047.
- ^ a b c d Levesque, Emily M.; Massey, Philip; Olsen, K. A. G.; Plez, Bertrand; Josselin, Eric; Maeder, Andre; Meynet, Georges (2005). "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought". The Astrophysical Journal. 628 (2): 973. arXiv:astro-ph/0504337. Bibcode:2005ApJ...628..973L. doi:10.1086/430901.
- ^ Berlanas, S. R.; Maíz Apellániz, J.; Herrero, A.; Mahy, L.; Blomme, R.; Negueruela, I.; Dorda, R.; Comerón, F.; Gosset, E.; Pantaleoni González, M.; Molina Lera, J. A.; Sota, A.; Furst, T.; Alfaro, E. J.; Bergemann, M. (2023-03-01). "Gaia-ESO survey: Massive stars in the Carina Nebula. I. A new census of OB stars". Astronomy and Astrophysics. 671: A20. arXiv:2301.08310. Bibcode:2023A&A...671A..20B. doi:10.1051/0004-6361/202245335. ISSN 0004-6361. RT Carinae's database entry at VizieR.
- ^ a b Davies, Ben; Beasor, Emma R. (March 2020). "The 'red supergiant problem': the upper luminosity boundary of Type II supernova progenitors". MNRAS. 493 (1): 468–476. arXiv:2001.06020. Bibcode:2020MNRAS.493..468D. doi:10.1093/mnras/staa174. S2CID 210714093.
- ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
- ^ Pickering, E. C.; Bailey, S. I.; Fleming, W. P.; Leland, E. F.; Wells, L. D. (March 1898). "Variable star clusters. New variable stars". Astrophysical Journal. 7: 208–211. Bibcode:1898ApJ.....7..208P. doi:10.1086/140457.
- ^ Cannon, Annie J. (1907). "Second catalogue of variable stars". Annals of Harvard College Observatory. 55: 1–94. Bibcode:1907AnHar..55....1C.
- ^ Kiss, L. L.; Szabó, Gy. M.; Bedding, T. R. (2006). "Variability in red supergiant stars: Pulsations, long secondary periods and convection noise". Monthly Notices of the Royal Astronomical Society. 372 (4): 1721–1734. arXiv:astro-ph/0608438. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x. S2CID 5203133.
- ^ Smith, Nathan (2006). "A census of the Carina Nebula - I. Cumulative energy input from massive stars". Monthly Notices of the Royal Astronomical Society. 367 (2): 763–772. arXiv:astro-ph/0601060. Bibcode:2006MNRAS.367..763S. doi:10.1111/j.1365-2966.2006.10007.x. S2CID 14060690.
- ^ Forte, J. C.; Marraco, H. G. (1986). "RT Carinae; a late type supergiant within an elongated dusty nebula". Astrophysical Letters. 25: 39. Bibcode:1986ApL....25...39F.