Rho² Arietis

Rho² Arietis is an M-type red giant star in the northern constellation of Aries. With an annual parallax shift of 9.28 mas,^[1] it is approximately 350 light-years (110 parsecs) distant from the Earth.

ρ² Arietis

Location of ρ2 Arietis (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Aries
Right ascension	02h 55m 48.49800s[1]
Declination	+18° 19′ 53.9029″[1]
Apparent magnitude (V)	5.93[2] (5.45–6.01)[3]
Characteristics
Spectral type	M6 III[4]
U−B color index	+1.12[2]
B−V color index	+1.51[2]
R−I color index	2.17[5]
Variable type	SRb[3]
Astrometry
Radial velocity (Rv)	+46.0[6] km/s
Proper motion (μ)	RA: −7.78[1] mas/yr Dec.: −14.98[1] mas/yr
Parallax (π)	9.28 ± 0.30 mas[1]
Distance	350 ± 10 ly (108 ± 3 pc)
Absolute magnitude (MV)	+0.60[7]
Details
Mass	1.14±0.2[8] M☉
Luminosity	1,995[9] L☉
Surface gravity (log g)	0.30[10] cgs
Temperature	3,341[8] K
Metallicity [Fe/H]	–0.24[10] dex
Other designations
ρ2 Ari, 45 Arietis, RZ Arietis, BD+17 457, HD 18191, HIP 13654, HR 867, SAO 93189.[11]
Database references
SIMBAD	data

Rho² Arietis is classified as a semiregular variable star with periods of 49.9 and 54.8 days.^[12] It varies in visual magnitude between 5.45 and 6.01. It has the variable star designation, RZ Arietis.^[3] It is generally considered to be an asymptotic giant branch star, having exhausted its core helium.^[13] Based on comparison of its current temperature and luminosity with theoretical evolutionary tracks, its initial mass is estimated to have been 1.3 M_☉ and its mass now is 1.14 M_☉.^[8]