R Scuti

R Scuti
Location of R Scuti (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scutum
Right ascension 18h 47m 28.95s
Declination −05° 42 18.5
Apparent magnitude (V) 4.2–8.6
Characteristics
Evolutionary stage Asymptotic giant branch
Spectral type G0Iae-K2p(M3)Ibe
U−B color index 1.53
B−V color index 1.47
Variable type RV Tau
Astrometry
Radial velocity (Rv)43.80 km/s
Proper motion (μ) RA: −45.399 mas/yr
Dec.: −32.410 mas/yr
Parallax (π)0.8572±0.2549 mas
Distanceapprox. 4,000 ly
(approx. 1,200 pc)
Absolute magnitude (MV)~ −2 – −3
Details
Mass0.55–0.68 M
Radius160 R
Luminosity9,400 L
Surface gravity (log g)0.0 cgs
Temperature4,500 K
Metallicity [Fe/H]–0.4 dex
Other designations
HD 173819, HIP 92202, 2MASS J18472894-0542185, SAO 142620, BD−05°4760, AAVSO 1842-05
Database references
SIMBADdata

R Scuti (R Sct) is a star in the constellation of Scutum. It is a yellow supergiant and is a pulsating variable known as an RV Tauri variable. It was discovered in 1795 by Edward Pigott at a time when only a few variable stars were known to exist.