Alpha Ursae Majoris A/B

Stars of Ursa Major, including Dubhe
Observation data
Epoch J2000      Equinox J2000
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.
Database references
SIMBAD data

Get more info about Dubhe in Wikipedia

This article uses material from the Wikipedia article
Dubhe, which is released under the Creative Commons Attribution-Share-Alike License 3.0