RT Carinae

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RT Carinae
Carina constellation map.png
Location of RT Car
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Carina
Right ascension 10h 44m 47.14715s[1]
Declination −59° 24′ 48.1296″[1]
Apparent magnitude (V) 8.36[2] (8.2 - 9.9[3])
Characteristics
Spectral type M2 Iab[4]
B−V color index +2.31[2]
Variable type LC[3]
Astrometry
Radial velocity (Rv) −20.91[5] km/s
Proper motion (μ) RA: −8.31[1] mas/yr
Dec.: 2.30[1] mas/yr
Parallax (π) 2.28 ± 1.03[1] mas
Distance approx. 1,400 ly
(approx. 400 pc)
Absolute magnitude (MV) −6.74[2]
Details[2]
Radius 1,090 R
Luminosity (bolometric) 184,000 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 (HD 303310, HIP 52562, SAO 238424) is a variable star in the Carina Nebula in the constellation Carina. It has a mean apparent magnitude of +8.55.

RT Carinae is a red supergiant with a spectral type of M2 Ia and has a temperature of 3,625 K. With a diameter over 1,000 times the Sun, it is one of the largest stars known. The luminosity is estimated to be 184,000. It is close to the open cluster Trumpler 15, but is not thought to be a member.[6] It appears to be surrounded by a dusty nebule, possibly material ejected from the star itself.[7]

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.[8]

References[edit]

  1. ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. 
  2. ^ 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/0504337Freely accessible. Bibcode:2005ApJ...628..973L. doi:10.1086/430901. 
  3. ^ a b 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. 
  4. ^ 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. 
  5. ^ Mermilliod, J. C.; Mayor, M.; Udry, S. (2008). "Red giants in open clusters. XIV. Mean radial velocities for 1309 stars and 166 open clusters". Astronomy and Astrophysics. 485: 303. Bibcode:2008A&A...485..303M. doi:10.1051/0004-6361:200809664. 
  6. ^ 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. arXiv:astro-ph/0601060Freely accessible. Bibcode:2006MNRAS.367..763S. doi:10.1111/j.1365-2966.2006.10007.x. 
  7. ^ 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. 
  8. ^ 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. arXiv:astro-ph/0608438Freely accessible. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x.