R Trianguli (abbreviated as R Tri) is a short-period oxygen-rich[4] Mira variable in Triangulum with a period of 266.9 days,[2] discovered by T. H. E. C. Espin in 1890.[7] It is losing about 1.1×10−7 M/yr, close to average for a short-period Mira variable.[8] While most short-period Mira variables reside in the Galactic halo, R Trianguli is a member of the thick disk, and its proper motion is fairly high for its distance.[4] Its angular diameter in the K band was measured in 2002 to be, on average, 5.22±0.30 mas, with a shape suggesting that there is an optically thin disk structure surrounding the star.[4]

R Trianguli
Location of R Trianguli (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Triangulum
Right ascension 02h 37m 02.340s[1]
Declination +34° 15′ 51.34″[1]
Apparent magnitude (V) 5.4–12.6[2]
Characteristics
Spectral type M3.5-8IIIe[2]
Apparent magnitude (B) 8.524±0.018
Apparent magnitude (G) 6.699±0.055
Apparent magnitude (R) 8.24
Apparent magnitude (J) 2.23±0.27
Apparent magnitude (H) 1.36±0.22
Apparent magnitude (K) 1.05±0.21
Variable type Mira[2]
Astrometry
Radial velocity (Rv)67.52±0.88[1] km/s
Proper motion (μ) RA: +34.272 mas/yr[1]
Dec.: −10.683 mas/yr[1]
Parallax (π)2.4334 ± 0.2487 mas[1]
Distanceapprox. 1,300 ly
(approx. 410 pc)
Details
Mass1.71[3] M
Radius196±41[4] R
Luminosity1,784[5] L
Surface gravity (log g)−0.09[1] cgs
Temperature3184±120[4] K
Other designations
R Tri, HR 758, HD 16210, HIP 12193, 2MASS J02370234+3415513, Gaia DR2 134874621777526400, Gaia DR3 134874621778128896[6]
Database references
SIMBADdata
A visual band light curve for R Trianguli, plotted from AAVSO data[9]

References

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  1. ^ a b c d e f 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.
  2. ^ a b c d "General Catalog of Variable Stars table at VizieR". vizier.cds.unistra.fr.
  3. ^ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. eISSN 1432-0746. ISSN 0004-6361.
  4. ^ a b c d e Thompson, R. R.; Creech-Eakman, M. J.; Akeson, R. L. (May 2002). "Time-dependent Asymmetries in the Atmosphere of the Mira Variable R Trianguli through Infrared Interferometry". The Astrophysical Journal. 570 (1): 373–378. Bibcode:2002ApJ...570..373T. doi:10.1086/339736. S2CID 121032726.
  5. ^ 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): 343–57. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352.
  6. ^ "V* R Tri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-06-29.
  7. ^ Gore, John Ellard (1903). The Stellar Heavens: An Introduction to the Study of the Stars and Nebulæ. Chatto & Windus. p. 52.
  8. ^ Jura, M. (February 1994). "The origin and evolution of short-period Miras in the solar neighborhood: Constraints on the life cycle of old stars". The Astrophysical Journal. 422: 102. Bibcode:1994ApJ...422..102J. doi:10.1086/173707.
  9. ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.