M81 is probably one of the most popular galaxies among the celestial objects of the northern hemisphere. Discovered by Johann E. Bode in 1774, M81 is located in the constellation "Big dipper". Shining at 7m0 visually she makes a wonderful target for a bino-viewer, as this sprial-galaxy is considerably large, measuring ~ 27x14 arc minutes (Compare the full moon appears at 31 arc minutes). In a distance of about 12 Mio LY, this galaxy is a bout 4 times more distant than the famous Andromeda-galaxy, the largest galaxy visible from the northern hemisphere. M81 is only the most prominent "star" of a bunch of galaxies, called the M81-group: M82, NGC 2403, NGC 2976, Holmerbg IX, NGC 3077 and others render further members of this group. In a decent amateur telescope (above 16" aperture), however, M81 reveals her entire beauty, as you can then gaze into the spiral arms and see the very bright core, that, by the way, houses a super massive black hole, which comprises perhaps 100 Mio solar masses.

In regards to gravity, M81 is engaged to M82, respectfully. Actually these two are bound together by gravity and therefor rotate around a common center of gravity, bringing them quite close to each other. At present (presence would be what we humans of the 21st century can gather now) our own galaxy, the milkiway would merely fit inbetween M81-82; expressed in numbers we are looking at 120.000 LY distance between the two. M81-82 is fabeld to have gone through a severe interactive gravitational encounter some hundreds of million years ago. As a result, huge masses of gas, dust and also stars are strewn inbetween the two galaxies. Whenever galaxies collide or at least come close to eachother, serious changes take place, metamorphing the original phenotypical appearance of both galaxies. Consequently, M82 has turned into a so called "star-burst" galaxy, nursing now millions of new stars, which could be addressed as "off-spring" of such a galactic interaction.

In the image you might notice a small little irrgular looking structure a little above the galaxy and a little to the left. This object is a small satelltie-galaxy of M81, called Holmberg IX, named after its discoverer Erik B. Homlberg, a swedish astronomer of the last century. Near the bottom and a little to the left is one of a typical background galaxies, named PGC 29505, shining at about 17m0.

When Gerlinde Kaltenbrunner hovers in the highest mountains of the world, she might be able to spot this galaxy with bare eyes !