M81, the large type Sb spiral galaxy near the bottom, and M82, the irregular galaxy on top, are at the center of a small group of galaxies which, in intergalactic terms, is located in our neighborhood, about 7 million light years distant.

M81 is one of the brightest spiral galaxies to be seen in a telescope, and is easily visible in binoculars. It has a "grand-design" spiral pattern, meaning it has pronounced spiral arms which are clearly defined around the whole galaxy. It is a spiral galaxy not unlike our own. In 1993, a type II supernova (1993J) occurred in M81, which reached a brightness of about mag 10.5 in its maximum. M81 was originally discovered by Johann Bode, who found it, together with its neighbor M82, in 1774.

M82 is a prototype "disk" irregular galaxy, and a starburst galaxy, meaning it is currently in a state of explosion-like starbirth which is triggered by infalling material. This material can be seen as red glow on both sides of the galaxy and as several dark lanes running across the galaxy near its center. In the infrared light, M82 is the brightest galaxy in the sky; it exhibits a so-called infrared excess. The cause for the galaxy's activity has probably been a close encounter with M81, which also triggered the formation of 100 young globular clusters which have been discovered with the Hubble Space Telescope.

One of M81's satellite galaxies is the bluish patch found immediately to the east (left) of M81: Holmberg IX (UGC 5336). This galaxy was first listed by Sidney van den Bergh. It was designated als Holmberg IX in Eric Holmberg's study of groups of galaxies (Holmberg 1969). It is an irregular dwarf galaxy of the Magellanic type (i.e. similar to the Magellanic Clouds), closely resembling Local Group galaxy IC 1613.

Also, if you look closely, numerous small background galaxies can be found within this photograph.

M81, an enlargement of this photograph.