R Ursae Minoris
Star in the constellation Ursa Minor
From Wikipedia, the free encyclopedia
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]
| 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 | |
| Evolutionary stage | AGB[4] |
| 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[5] (var) |
| Details | |
| Mass | 1.71[6] M☉ |
| Radius | 686[7] R☉ |
| Surface gravity (log g) | −0.46[6] cgs |
| Temperature | 2,875[6] K |
| Metallicity [Fe/H] | +0.07[6] dex |
| Other designations | |
| R UMi, BD+72°732a, HD 149683, HIP 80802[8] | |
| Database references | |
| SIMBAD | data |
In 1881, Edward Charles Pickering announced that the star, at that time unnamed, is a variable star.[9] It was listed with its variable star designation, R Ursae Minoris, in Annie Jump Cannon's 1907 work Second Catalog of Variable Stars.[10]
