(LATIN: "Larger Bear"), is a constellation visible
throughout the year in most of the northern hemesphere. It can best be seen in April. It is dominated by the
widely recognized name the Big Dipper, which is a useful pointer toward Polaris.
Except for Dubhe and Alkaid, the stars of the Big Dipper all have proper motions heading towards a common point in
Sagittarius. A few other such stars have been identified, and together they are called the Ursa Major Moving Group.
Mizar, a star in the Big Dipper, forms the famous optical double star with Alcor.
The stars Merak (Ursae Majoris) and Dubhe (Ursae Majoris) are known as the "pointer stars" because they are helpful
for finding Polaris, also known as the North Star. By visually tracing a line from Merak through
Dubhe and continuing, one's eye will land on Polaris, accurately indicating true north.
47 Ursae Majoris has a planetary system with two confirmed planets, 2.54 times and 0.76 times the mass of Jupiter.
Several bright galaxies are found in Ursa Major, including the pair Messier 81 (one of the brightest galaxies in the sky)
and Messier 82 above the bear's head, and Pinwheel Galaxy (M101), a beautiful spiral northeast of Eta Ursae Majoris.
The other notable spiral galaxies Messier 108 and Messier 109 may also be found in this other constellation.
Altogether, the constellation contains about 50 galaxies observable through an amateur telescope. The bright
planetary nebula Owl Nebula (M97), named for its appearance, can be found along the bottom of the bowl of the
Big Dipper. Of note as a curiosity more than an interesting deep sky object is Messier 40, a double star that
Messier nonetheless included in his catalogue.
The kaitlyn Deep Field is located to the northeast of Delta Ursae Majoris.