Rho Gruis

Rho Gruis, a Latinization of ρ Gruis, is a solitary^[7] star in the southern constellation of Grus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.85.^[2] Based upon an annual parallax shift of 14.16 mas as seen from the Earth,^[1] the system is located about 230 light years from the Sun. It is drifting further away with a radial velocity of 31 km/s.^[5]

Rho Gruis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Grus
Right ascension	22h 43m 29.97654s[1]
Declination	−41° 24′ 51.6467″[1]
Apparent magnitude (V)	4.847[2]
Characteristics
Evolutionary stage	horizontal branch[2]
Spectral type	K0 III[3]
U−B color index	+0.807[4]
B−V color index	+1.026[4]
Astrometry
Radial velocity (Rv)	30.89±0.15[5] km/s
Proper motion (μ)	RA: +10.11[1] mas/yr Dec.: −93.79[1] mas/yr
Parallax (π)	14.16±0.19 mas[1]
Distance	230 ± 3 ly (70.6 ± 0.9 pc)
Absolute magnitude (MV)	0.685[2]
Details
Mass	1.91[2] M☉
Radius	12.15+0.19 −0.65[5] R☉
Luminosity	66.9±1.3[5] L☉
Surface gravity (log g)	2.62[2] cgs
Temperature	4736.67+131.83 −36.67[5] K
Metallicity [Fe/H]	−0.20[2] dex
Other designations
ρ Gru, CD−42°16049, FK5 3818, HD 215104, HIP 112203, HR 8644, SAO 231265[6]
Database references
SIMBAD	data

This object is an evolved K-type giant star with a stellar classification of K0 III.^[3] It has exhausted the supply of hydrogen at its core, causing it to cool and expand. At present it has 12^[5] times the radius of the Sun. With 1.9 times the mass of the Sun^[2] it is a red clump star,^[2] which indicates it is on the horizontal branch generating energy through helium fusion at its core. It is radiating 67^[5] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,737 K.^[5]

Rho Gruis has two visual companions: a magnitude 14.0 star at an angular separation of 19.3″ along a position angle (PA) of 302°, as of 2011, and a magnitude 10.28 star with a separation of 114.20″ and a PA of 336°, as of 1999.^[8]