This spiral galaxy was discovered in 1774 by German astronomer Johann Bode. Five years later Charles Messier identified the galaxy and added it to his famous catalog.

M81 is located about 12 million light years from Earth and appears in the northern constellation Ursa Major. At apparent magnitude 7, M81 is not visible to the naked eye. On the apparent magnitude scale, fainter objects have higher magnitudes, and the faintest objects visible to the naked eye have apparent magnitudes around 6. The scale is logarithmic, with a difference in magnitude of 1 representing an apparent brightness difference of about 2.5, so the faintest astronomical objects visible to the naked eye are about 2.5 times as bright as M81.

The individual stars seen in this image are much closer to us than M81, being members of our galaxy, the Milky Way. They are also too faint to be seen with the naked eye from Earth.

This image is a composite of 42 three minute exposures at ISO 400, taken under fairly poor sky conditions and with significant light pollution. Poor transparency resulted in varying brightness of the background sky glow from shot to shot. The 42 frames were processed along with 14 dark frames, 14 flat frames and 14 dark flat frames, using Iris software.