Constellation List
Star List
By Season
Alphabetical
Latitudes
Minneapolis, MN (45°N)
NorthPole (90°N)
Prudhoe Bay, AK (70°N)
St.Petersburg,
Russia(60°N)
Prague, C.R. (50°N)
Philadelphia, PA (40°N)
Albuquerque, NM (35°N)
New Orleans, LA (30°N)
Santiago, Cuba (20°N)
Caracas,
Venezuela (10°N)
Quito, Ecuador (0°N)
Port Moresby,
New Guinea(10°S)
Porto Alegre,
Brazil (30°S)
Montevideo,
Uruguay(35°S)
Queenstown, NZ (45°S)
South Pole (90°S)
Bibliography and Credits
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Dubhe
(DUB-ee)
Alpha Ursae Majoris
Names For This Star
The name Dubhe derives from the Arabic phrase Thahr al Dubb al Akbar meaning "The Back of the Greater Bear".
Description of the Star
Dubhe is an orange K0IIIa giant. The spectral type implies an effective temperature of 4500 K, a mass 4 times that of the sun and 16 times the diameter.
Dubhe's Companion
Dubhe has a companion, Dubhe B, separated by 0.672 sec of arc corresponding to a projected distance of 25 AU. The companion appears to be a yellowish F0V main sequence star of about 7400 K temperature, with a mass 1.7 times that of the sun and with 1.3 times the diameter. The Visual Magnitude of the companion is about 4.73.
The combined luminosity of Dubhe and its companion is about 230 times that of the sun.
Dubhe C
There is a third star apparently physically associated with the Dubhe system. Dubhe C is an F8 star of Visual Magnitude 7.12 separated by 280 sec of arc from Dubhe A. This corresponds to a projected distance of about 11,000 AU or 0.17 ly.
The spectrum of Dubhe C indicates that it has itself a near companion that in a 6.4 day orbit.
Other Designations For This Star
Flamsteed |
50 Ursae Majoris |
Hipparcos Identifier (HIP Number) |
54061 |
Harvard Revised (HR Number) |
4301 |
Henry Draper Catalog (HD Number) |
95689 |
Bonner Durchmusterung (BD Number) |
BD+62 1161 |
Smithsonian Astrophysical
Observatory compendium (SAO Number) |
15384 |
Fundamental Katalog (FK5 Number) |
417 |
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