Particulars:
General:
Constellation of the northern hemisphere; in central europe
this constellation never touches the horizon.
Ursa Majoris is a good starting point to find other stars and
constellation in the sky (see "how to find
constellations"):
Following the line leading from alpha UMa to beta UMa,
one can find easily the pole star (Polaris, alphastar of the
Little Bear).
The constellation Charioteer (Auriga) can be found when following
the line leading from delta UMa to alpha UMa. Its
leading directly to alpha Aur (Capella).
Drawing a line from delta UMa to beta UMa and
beyond, you will find alpha Gem (Castor in the
constellation Twins).
This constellation is most famous for the asterism ">Big
Dipper, build by the stars alpha UMa, beta UMa, gamma
UMa, delta UMa, epsilon UMa, zeta UMa and eta UMa.
Additional image available: Chart with deepsky objects
Stars and objects
The multiple star system zeta UMa (called Mizar
- from the arabian word for girdle) belongs to the most famous
multiple stars in the sky. It's brightness is about 2.4 mag;
therefore under very good conditions it is possible for the naked
eye to see the 4th mag. companion, called 'Alcor' or 80 UMa
(otherwise a small binocular will help). In small telescops
another 4th mag star becomes visible. Each of these stars is as
well a spectroscopic binary.
Xi UMa is a binary with an orbiting period of 60 years. At
the point when they seemed to be farthest away from each other
they can be viewed with smaller scopes (as it was the case 1975),
but at their closest (in 1992) one needs at least an aperture of
15 cm to resolve the components.
Even with smaller scopes M81 is worth for observing. On
photographs it reveals one of the most beautiful spirals in the
sky. Please check the Messier Database for more info about M81
and M82.
Mythological Background:
According to greek mythology one day the Godfather Zeus saw a
beautiful girl, the nymph Callisto, and fell in love with her.
But Callisto was one of the virgin followers of the virgin
goddess Diana, the huntress. So Zeus took the form of Diana to
approach Callisto and managed it to make love to her.
Once Diana saw what had happened (Callisto was obviously
pregnant, when Diana and all her nymphs take a bath), she send
Callisto away. Even worse, Hera, the wife of Zeus heard about
Callisto and her now born son Arkas and become terribly jealous.
In her anger she turned her into a bear.
Years later Callisto, still a bear, met her son Arkas, but was of
course not recognized by him. In his fear Arkas tried to kill the
bear, but Zeus himself took both of them an placed them between
the stars and made them two neighbouring constellations.
When Hera saw Callisto glittering with the stars she furiously
went down to the ocean to meet Thethys and Oceanos. She told them
the story and ask a favour: that the bear never ever is able to
reach the water. And indeed, as said above, in the northern
hemisphere, the constellation of the Great Bear never touches the
ocean. (This story can be found in "Metamorphoses, book
II" by the roman poet Ovid (Publius Ovidius Naso, 43 BC to
17 AC). Its's an intersting that he speaks of the seven stars of
the Bear. This implies that in those times just the stars forming
the asterism of the Big Dipper were meant to form the bear.
Though these stars are even nowadays called the Great Bear, the
constellation is a bit more extended.)