M81 and M82 Galaxies  
Scope: Deep Sky Instruments RC10c 254mm @ f/7.4 / FL= 1880mm Corrected Ritchey Chretien  
Camera: FLI- ML11002M with FLI (7 position filter wheel CFW-5-7) 
Total Exposure: Luminance= 9.8 hr / Red= 3.3 hr / Green= 2.0 hr / Blue= 1.5 hr
April 2013: Chico, California, USA 
Comments: Messier 81( on the right) is the largest galaxy in this group, located in the constellation Ursa Major. At approximately 11.7 Mly from the Earth, it makes this group and the Local Group, containing the Milky Way, relative neighbors in the Virgo Supercluster. Gravitational interactions of M81 with M82 have stripped hydrogen gas away, forming gaseous filamentary structures in the group. Moreover, these interactions have allowed interstellar gas to fall into the centers of M82, leading to vigorous star formation or starburst activity there.