R Ursae Minoris

R Ursae Minoris is a star in the constellation Ursa Minor. A red giant of spectral type M7IIIe, it is a semiregular variable ranging from magnitude 8.5 to 11.5 over a period of 325 days.^[3]

R Ursae Minoris

A visual band light curve for R Ursae Minoris, plotted from AAVSO data[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Ursa Minor
Right ascension	16h 29m 57.8923s[2]
Declination	+72° 16′ 49.166″[2]
Apparent magnitude (V)	8.5-11.5[3]
Characteristics
Spectral type	M7IIIe[3]
Variable type	semiregular variable[3]
Astrometry
Proper motion (μ)	RA: 11.973±0.085[2] mas/yr Dec.: 13.976±0.092[2] mas/yr
Parallax (π)	2.6648±0.0629 mas[2]
Distance	1,220 ± 30 ly (375 ± 9 pc)
Absolute magnitude (MV)	+2.461[4] (var)
Details
Mass	1.71[5] M☉
Radius	686[6] R☉
Surface gravity (log g)	−0.46[5] cgs
Temperature	2,875[5] K
Metallicity [Fe/H]	+0.07[5] dex
Other designations
R UMi, BD+72°732a, HD 149683, HIP 80802[7]
Database references
SIMBAD	data

In 1881, Edward Charles Pickering announced that the star, at that time unnamed, is a variable star.^[8] It was listed with its variable star designation, R Ursae Minoris, in Annie Jump Cannon's 1907 work Second Catalog of Variable Stars.^[9]