R Trianguli

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

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]

A visual band light curve for R Trianguli, plotted from AAVSO data[9]
  1. ^ a b c d e f Cite error: The named reference dr3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference VizieR was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference kervella2022 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference thompson2002 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference mcdonald2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference gore1903 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference jura1994 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference aavso was invoked but never defined (see the help page).