R Carinae

The visual band light curve of R Carinae, from AAVSO data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Carina
Right ascension 09h 32m 14.59964s[2]
Declination −62° 47′ 20.0452″[2]
Apparent magnitude (V) 3.9 - 10.5[3]
Characteristics
Evolutionary stage AGB[4]
Spectral type M6/7pe[5]
B−V color index 0.906±0.009[6]
Variable type Mira[3]
Astrometry
Radial velocity (Rv)+28.1±1.0[6] km/s
Proper motion (μ) RA: −37.900[2] mas/yr
Dec.: +22.232[2] mas/yr
Parallax (π)2.5813 ± 0.4460 mas[2]
Distanceapprox. 1,300 ly
(approx. 390 pc)
Absolute magnitude (MV)1.48[6] (at mv = 7.43)
Details
Mass0.87+0.47
−0.31[4] M☉
Radius241.0+37.6
−32.6[4] R☉
Luminosity4,571+1,331
−1,031[4] L☉
Temperature2,800[7] K
Other designations
R Car, CD−62°396, GC 13192, HD 82901, HIP 46806, HR 3816, SAO 250614, CCDM J09322-6247, WDS J09322-6247AB[8]
Database references
SIMBADdata

R Carinae is a double star in the southern constellation of Carina. The brighter component is a variable star that can be viewed with the naked eye at peak brightness,[9] but is usually too faint to be seen without a telescope, having an apparent visual magnitude that fluctuates around 7.43.[6] This star is located at a distance of approximately 1,300 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +28 km/s.[6]

The main component is an aging red giant star on the asymptotic giant branch[4] with a stellar classification of M6/7pe.[5] It is classified as a pulsating Mira type variable star and its visual brightness varies with an average amplitude of 4.25 magnitudes over a period of 303.99±1.08 d. Its average maximum visual magnitude is 5.05±0.45,[9] but the brightest observed maximum was magnitude 3.9[3] This star is surrounded by a dusty shell, with properties that are consistent with iron-poor silicates or corundum, extending from around three stellar radii outward.[10]

The companion is a magnitude 11.30 star at an angular separation of 2.10″ along a position angle of 132° from the main star, as of 2015.[11]

References

  1. ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  2. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  3. ^ a b c Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  4. ^ a b c d e Takeuti, Mine; et al. (2013), "A Method to Estimate the Masses of Asymptotic Giant Branch Variable Stars", Publications of the Astronomical Society of Japan, 65 (3): 60, Bibcode:2013PASJ...65...60T, doi:10.1093/pasj/65.3.60.
  5. ^ a b Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  6. ^ a b c d e Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  7. ^ McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  8. ^ "R Car". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-30.
  9. ^ a b Vogt, N.; et al. (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, S2CID 119295645.
  10. ^ Ireland, M. J.; et al. (July 2005), "Dust scattering in the Miras R Car and RR Sco resolved by optical interferometric polarimetry", Monthly Notices of the Royal Astronomical Society, 361 (1): 337–344, arXiv:astro-ph/0505112, Bibcode:2005MNRAS.361..337I, doi:10.1111/j.1365-2966.2005.09181.x, S2CID 14724805.
  11. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
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