5 Ursae Minoris
Star in the constellation Ursa Minor
From Wikipedia, the free encyclopedia
5 Ursae Minoris is a star in the circumpolar constellation of Ursa Minor. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.253.[2] The distance to this star, as determined from an annual parallax shift of 9.09±0.13 mas,[1] is about 110 pc. It is moving further away with a heliocentric radial velocity of +9 km/s.[2]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Minor |
| Right ascension | 14h 27m 31.54335s[1] |
| Declination | +75° 41′ 45.5717″[1] |
| Apparent magnitude (V) | 4.253[2] |
| Characteristics | |
| Spectral type | K4-III[3] |
| B−V color index | 1.457[2] |
| Astrometry | |
| Radial velocity (Rv) | +9.34[2] km/s |
| Proper motion (μ) | RA: +8.79[1] mas/yr Dec.: +21.76[1] mas/yr |
| Parallax (π) | 9.09±0.13 mas[1] |
| Distance | 359 ± 5 ly (110 ± 2 pc) |
| Absolute magnitude (MV) | −0.96[4] |
| Details | |
| Mass | 1.86[2] M☉ |
| Radius | 16[5] R☉ |
| Luminosity | 447[2] L☉ |
| Surface gravity (log g) | 1.91[6] cgs |
| Temperature | 4,095±39[2] K |
| Metallicity [Fe/H] | −0.16[6] dex |
| Rotational velocity (v sin i) | 1.9[7] km/s |
| Age | 2.00[2] Gyr |
| Other designations | |
| 5 UMi, NSV 6687, BD+76°527, FK5 1379, HD 127700, HIP 70692, HR 5430, SAO 8024, WDS J14275+7542A[8] | |
| Database references | |
| SIMBAD | data |
With an age of around two billion years, this is an evolved red giant with a stellar classification of K4-III;[3] a star that has used up its core hydrogen and has expanded. It is a mild barium star, which may indicate it is a binary with a white dwarf companion,[9] and is very lithium-weak.[10] The star has an estimated 1.86[2] times the mass of the Sun and has expanded to about 16[5] times the Sun's radius. It is radiating 447[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,095 K.[2]
In Chinese astronomy, this star is named Shuzi, the son of a concubine. It forms the asterism Beiji (Northern Pole) with γ Ursae Minoris, β Ursae Minoris, 4 Ursae Minoris, and Σ 1694.[11]