M81 & M82
Bode's Galaxy and the so-called Cigar Galaxy are gravitationally linked. It's believed that M82's extensive star-burst activity (the "exploding" centre of the smaller galaxy) has been caused by tidal interaction with the larger, denser M81. This photo represents about 1.5 hours of HaRGB from urban Victoria with a 5-inch apo refractor, March 3, 2019, and recently re-processed.