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.
Dubhe
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What's in a Name: ...
Dubhe = Alpha Ursae Majoris
Merak = Beta Ursae Majoris
Phecda = Gamma Ursae Majoris
Megrez = Delta Ursae Majoris
Alioth = Epsilon Ursae Majoris
Mizar = Zeta Ursae Majoris
Alkaid = Eta Ursae Majoris
Theta UMa = Theta Ursae Majoris ...
Eilean DubhEilean Dubh MórEilean Glas, Scalpay
Eilean GlasEilean Mhic CoinnichEilean Righ
Eileen, WisconsinEileenEileen (musical) ...
Named Stars: DUBHE (Alpha UMa) MERAK (Beta UMa) PHAD (Gamma UMa) MEGREZ (Delta UMa) ALIOTH (Epsilon UMa) MIZAR (Zeta UMa) ALCOR (80 UMa)
Once you find and identify the Big Dipper you can use it to find many other stars and constellations.
Imagine the lines of right ascension - zero for Chaph, 11 for Merak and Dubhe (the "pointer stars"), 12 for Phad, and 14 for Alkaid.
Practise using your hands to measure angles in the sky.
Two stars in Ursa Major called Dubhe and Merak are popularly termed the Pointers because a line drawn through them points to the north celestial pole.
If you draw an imaginary line from Merak through Dubhe out of the cup of the dipper (see the picture above) and continue five times as far as Dubhe is from Merak, you will arrive at Polaris, the North Star.
[8316] alpha Ursae Majoris or Dubhe ("bear") is the second brightest star in Ursa Major and one of the Pointers, two stars that point toward Polaris, the North Star. Dubhe is a red giant approximately 124 light-years distant.
After a good Easy Alignment (using Sirius and Dubhe - not very far apart in RA), I found that I probably need to retrain the drives. GoTos were still reasonably good - maybe 5 arc-minutes or so, but I think it was a bit better before.
This star, alpha UMa (Dubhe: the Bear), is a yellow giant, about 25 times the size of the Sun, and 86 light years away. It is a close visual binary, discussed below.
Named stars: Alpha UMa (Dubhe), Beta UMa (Merak), Gamma UMa (Pháchd/Phekda), Delta UMa (Megrez), Epsilon UMa (Alioth), Zeta UMa (twin star Alkor+Mizar), Eta (Benetnasch/Alkaid).
Alcor (Saidak, 80 UMa), Alioth (ε UMa), Alkaid (Benetnash, η UMa), Alula Australis (ξ UMa), Alula Borealis (ν UMa), Dubhe (α UMa), Megrez (Kaffa, δ UMa), Merak (β UMa), Mizar (ζ UMa), Muscida (ο UMa), ...
The two brightest stars in the Big Dipper (Dubhe and Merak, marked numbers 1 and 2 on the picture above) "point" to the North Star.
The star at the bottom of the Big Dipper's bowl closest to the handle. A line from Phecda to Dubhe and an equal distance past it points to the location of the galaxies M81 and M82.
89
Sabik ...
BIG DIPPER
The Big Dipper is a group of 7 stars (an ) contained in the Northern Hemisphere (The Great Bear). The two brightest stars in the Big Dipper (Dubhe and Merak) "point" to the North Star, .
1,000,000,000 ...
URSA MAJOR
Ursa Major (The Great Bear) is a well-known constellation in the Northern Hemisphere that contains the 7 stars of the Big Dipper. The two brightest stars in Ursa Major (Dubhe and Merak) "point" to the current North Star, Polaris.
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Deneb Kaitos Schemali Iota Ceti
Denebola Beta Leonis
Dheneb Eta Ceti
Diadem Alpha Comae Berenices
Diphda Beta Ceti
Dnoces Iota Ursae Majoris
Dschubba Delta Scorpii
Dubhe Alpha Ursae Majoris
Duhr Delta Leonis ...
on the sky is about five times the angle between the two stars at the end of the cup of the Big Dipper. Because they are so useful for finding the all-important North Star, these two stars are known as the Pointer Stars. They are also called Dubhe ...
Shield Ser Serpens Serpens Unuk Sex Sextans Sextant Tau Taurus Bull Aldebaran Tel Telescopium Telescope TrA Triangulum Australis Southern Triangle Ras al Muthallath (Atria) Tri Triangulum Triangle Tuc Tucana Toucan UMa Ursa Maior Great Bear Dubhe UMi ...
 See also: Merak, Star, Ursa Major, Constellation, Sky
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