R Trianguli Australis

R Trianguli Australis

A light curve for R Trianguli Astralis, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Triangulum Australe
Right ascension 15h 19m 45.71231s[2]
Declination −66° 29′ 45.7417″[2]
Apparent magnitude (V) 6.73[3] (6.33 - 6.90)[4]
Characteristics
Spectral type F7 Ib/II[5]
Variable type δ Cep[6]
Astrometry
Radial velocity (Rv)−13.2±1.6[7] km/s
Proper motion (μ) RA: −5.113[2] mas/yr
Dec.: −8.317[2] mas/yr
Parallax (π)1.4754 ± 0.0371 mas[2]
Distance2,210 ± 60 ly
(680 ± 20 pc)
Absolute magnitude (MV)2.69[8]
Details
Mass5.42 or 5.66[9] M☉
Radius24.7±1.9[10] or 35.8±0.8[9] R☉
Surface gravity (log g)2.10[9] cgs
Temperature5,852±21[9] K
Metallicity [Fe/H]+0.06±0.08[8] dex
Rotational velocity (v sin i)16 km/s
Other designations
R TrA, CD−66° 1728, HD 135592, HIP 75018, SAO 253107[11]
Database references
SIMBADdata

R Trianguli Australis is a yellow-white hued variable star in the southern constellation Triangulum Australe. It is near the limit of visibility to the naked eye, having a typical apparent visual magnitude of 6.73.[3] Based upon an annual parallax shift of 1.48 mas,[2] it is located 2,210 light years away. R TrA is moving closer with a heliocentric radial velocity of −13 km/s.[7]

This is a Classical Cepheid variable with an apparent magnitude that ranges from 6.33 to 6.90 over 3.38926 days.[4] It is a bright giant/supergiant with a nominal stellar classification of F7 Ib/II,[5] but pulsates between spectral types F5Ib/II-G5.[4] Depending on the method employed, the estimated mass is 5.42 or 5.66 times the mass of the Sun and it has 24.7 or 35.8 times the Sun's radius.[9] R TrA has an infrared excess that is being emitted by circumstellar silicate dust heated to 150–200 K. It is losing mass at the rate of 4×10−9 M☉·y−1.[9]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference AAVSOR was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Luck2011 was invoked but never defined (see the help page).
  9. ^ a b c d e f Cite error: The named reference usenko2014 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference moskalik was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).