This is another star chart of Ursa Major to help you recognize the constellation in the sky, but this time I added some greek letters next to some of the brightest stars so that we can attach the names to what you're seeing in the sky. I always find that my appreciation for the sky is enhanced when I know the names and a little bit about what I'm looking at--it gives me a feeling of familiarity and as a result the sky has become like an old friend. As you may know, many but not all of the brightest stars in the sky have proper names (ie: Betelgeuse in Orion). Another method of naming stars involves the use of Greek letters and the genitive case of the Latin name, known as the "Bayer name". For example, the Bayer name for Merak would be Beta Ursae Majoris (pronounced ER-sigh MAY-jor-iss). Anyway, this is a list of some of the major stars in Ursa Major with a brief description of each. Just match the star on the list to the greek letter in the picture!
Dubhe [Alpha (a) Ursae Majoris]: This star's name means Bear, but it is derived from an arabic phrase which means The Back of the Great Bear. Shining at magnitude +1.8, Dubhe is one of the two "pointer stars" in Ursa Major that can be used to locate the North Star. Dubhe has a magnitude +7 companion that is visible in small telescopes. You can find the companion star about 6.5' from Dubhe at position angle 204º. Dubhe is part of the "Big Dipper" asterism.
Merak [Beta (b) Ursae Majoris]: Meaning The loin of the bear, Merak is the second of the two "pointer stars" used to locate Polaris. It shines at magnitude +2.4 and is about 80 light years away. Merak is part of the "Big Dipper" asterism.
Phecda [Gamma (g) Ursae Majoris]: Sometimes this star is also refered to as Phad, but both names are derived from the same arabic name (Al Fahdh] which means "the Thigh". Shining at magnitude +2.4, Phecda lies approximately 90 light years away.
Megrez [Delta (d) Ursae Majoris]: Meaning "the root of the tail", Megrez is the dimmest of the "Big Dipper" stars at magnitude +3.3. But at a distance of only about 65 light years, Megrez is actually closer to us than brighter Phecda and Merak! Also, Megrez has an absolute magnitude of +1.9, compared to our own sun which has a +4.8 absolute magnitude. This means that if we placed our own Sun at Megrez's distance, it would no longer be visible!
Alioth [Epsilon (e) Ursae Majoris]: Although the meaning of this star's name is uncertain, there is no doubt that Alioth is the brightest of the seven stars that make up the "Big Dipper" asterism. Alioth shines at magnitude +1.8 from a distance of about 70 light years.
Mizar [Zeta (z) Ursae Majoris]: Although Mizar isn't overwhelmingly bright at magnitude +2.4, it is by far the most interesting of the seven "Big Dipper" stars! If you look carefully under reasonable sky conditions, you'll notice another star very close to Mizar (too close to be shown on the chart above). That star is Alcor, shining at magnitude +4.0 about 11.5 minutes of arc from Mizar! These two stars are commonly called "the Horse and Rider", with brighter Mizar representing the horse while Alcor is a dim rider. The Mizar/Alcor pair was considered a good test for visual acuity in medieval times (when skies were much darker than they are today). This is a little surprising because it seems to be rather easy to spot the two with the naked eye even from sites with some light pollution. The two stars apparently share the same proper motion, so it is unlikely that they have moved any farther apart. It seems more likely that Alcor may have brightened since the Horse and Rider were first used as a celestial eye-chart!
The view gets even more interesting through your small telescope. Using low to moderate power, you should be able to keep both Mizar and Alcor within the same field of view. But you'll also notice a couple of new surprises. First, you'll find that Mizar is an easy double star! In fact, it was the first double star to be discovered (in 1650 by Riccioli). The companion star is magnitude +4.0, located about 14.5 seconds of arc from the primary at position angle 151º. Also, you should be able to see a much dimmer star forming a triangle with Mizar and Alcor. This magnitude +8.8 star is Sidus Ludovicianum, named by a German astronomer in 1723. He apparently thought he had discovered a new planet or a recently formed star, and proceeded to name it in honor of his king, Ludwig V!
Alkaid [Eta (h) Ursae Majoris]: Shining at magnitude +1.9 from a distance of 210 light years, Alkaid is the end of the Big Dipper's handle. This star is a good starting point for locating M51, the Whirlpool Galaxy, which is actually in the neighboring constellation Canes Venatici.
Talitha [Iota (i) Ursae Majoris]: Shining at magnitude +3.1, Talitha represents the front feet of the Great Bear along with Kappa Ursae Majoris. Talitha is only about 50 light years away, but notice how dim it appears compared to some of the other more distant stars in Ursae Major!
Psi (y) Ursae Majoris: At only magnitude +3.0, this is not the most impressive star in the Great Bear. But this yellow giant star can be used to help us find 47 Ursae Majoris...to find out why 47 Ursae Majoris is so interesting and where to find it, see the Select Objects page.