![]() ![]() Stars of Ursa Major, including Dubhe |
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Observation data Epoch J2000 Equinox J2000 |
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Constellation | Ursa Major |
Right ascension | 11 |
Declination | +61° 45′ 03.7249″ |
Apparent magnitude (V) | 1.79 |
Characteristics | |
Spectral type | K1 II-III |
U−B color index | +0.93 |
B−V color index | +1.07 |
Variable type | Pulsating |
Astrometry | |
Radial velocity (Rv) | –9 km/s |
Proper motion (μ) | RA: –134.11 mas/yr |
Parallax (π) | 26.54 ± 0.48mas |
Distance | 123 ± 2 ly (37.7 ± 0.7 pc) |
Absolute magnitude (MV) | –1.10 ± 0.04 |
Orbit | |
Companion | α UMa B |
Period (P) | 44.4 yr |
Semimajor axis (a) | 0.603" |
Eccentricity (e) | 0.4 |
Inclination (i) | 152° |
Longitude of the node (Ω) | 2000° |
Periastron epoch (T) | 1956.8 |
Details | |
α UMa A | |
Surface gravity (log g) | 2.46 |
Temperature | 4,660K |
Metallicity [Fe/H] | –0.20 ± 0.07dex |
Rotational velocity (v sin i) | 2.6 ± 1.0 km/s |
Other designations | |
Dubhe, Dubb, Ak, 50 UMa, BD+62 1161, FK5 417, HD 95689, HIP 54061, HR 4301, SAO 15384.
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Database references | |
SIMBAD | data |