R Cassiopeiae

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
R Cassiopeiae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia
Right ascension  23h 58m 24.87003s[1]
Declination +51° 23′ 19.70″[1]
Apparent magnitude (V) 4.4 to 13.5[2]
Spectral type M6e–M10e[2]
U−B color index +0.08[3]
B−V color index +1.83[3]
Variable type Mira[2]
Radial velocity (Rv)−22.94±0.72[4] km/s
Proper motion (μ) RA: 81.920±0.403[1] mas/yr
Dec.: 18.760±0.358[1] mas/yr
Parallax (π)5.3417 ± 0.2449[1] mas
Distance610 ± 30 ly
(187 ± 9 pc)
Mass0.59[5] M
Radius263[5]–310[6] R
Luminosity3,837[5] L
Temperature2,812[5] K
Other designations
R Cas, BD+50°4202, HD 224490, HIP 118188, HR 9066, SAO 35938, ADS 17135, CCDM J23584+5123[7]
Database references

R Cassiopeiae is a variable star in the northern constellation of Cassiopeia. It is located approximately 610 light years distant from the Sun, but is drifting closer with a radial velocity of −23 km/s.[4] This is a pulsating Mira-type variable star with a brightness varies from magnitude +4.4 down to +13.5 with a period of 433.6 days.[2] At its maximum, R Cassiopeiae is visible to the naked eye as a faint, red-hued star.

This aging red giant star has a stellar classification that varies from M6e to M10e,[2] where the 'e' suffix indicates emission features in the spectrum. Currently on the asymptotic giant branch,[8] it has 59%[5] of the mass of the Sun with an oxygen rich chemical abundance.[9] Having exhausted the supply of hydrogen at its core, the star has expanded to 263[5]–310[6] times the Sun's radius. On average, the star is radiating 3,837[5] times the luminosity of the Sun from its swollen photosphere with an effective temperature ranging around 2,812 K.[5] It is losing mass at the rate of 5 × 10−7 M yr−1 and is surrounded by a dusty circumstellar shell that extends out to 2.8.[9]

See also[edit]


  1. ^ 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.
  2. ^ a b c d e 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.
  3. ^ a b Ducati, J. R. (2002). "Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
  4. ^ a b Famaey, B.; et al. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430 (1): 165–186. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272.
  5. ^ a b c d e f g h 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.
  6. ^ a b de Beck, E.; et al. (2010). "Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles. II. CO line survey of evolved stars: derivation of mass-loss rate formulae". Astronomy & Astrophysics. 523: A18. arXiv:1008.1083. Bibcode:2010A&A...523A..18D. doi:10.1051/0004-6361/200913771.
  7. ^ "R Cas". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-17.
  8. ^ Assaf, K. A. (December 2018). "Multi-epoch Proper Motion Magnetic Field Comparison of SiO Masers around R Cas". The Astrophysical Journal. 869 (1): 19. Bibcode:2018ApJ...869...80A. doi:10.3847/1538-4357/aaea65. 80.
  9. ^ a b Ueta, T.; et al. (May 2010). "The interface between the stellar wind and interstellar medium around R Cassiopeiae revealed by far-infrared imaging". Astronomy and Astrophysics. 514: 6. arXiv:0911.4918. Bibcode:2010A&A...514A..16U. doi:10.1051/0004-6361/200913455. A16.