M81 and M82 are a gravitationally interacting pair of galaxies in Ursa Major — one a textbook grand-design spiral, the other a chaotic starburst galaxy bearing the visible scars of their shared history.
Messier 81 and Messier 82 lie around 12 million light-years away in Ursa Major and are among the most studied galaxy pairs in the sky. M81 (Bode's Galaxy) is a large, well-defined spiral whose structure has been distorted by repeated close encounters with its neighbour. M82 (the Cigar Galaxy) shows the more dramatic consequences — a burst of intense star formation triggered by the gravitational interaction, driving enormous plumes of gas and dust out from its plane.
This was a target I came back to, and the two renders in the gallery tell that story. The earlier capture shows what was possible with the equipment and technique at the time. The later revisit — with improved gear and considerably more refined processing — reveals the difference that experience and iteration makes.
The pair sit close enough together on the sky to fit comfortably in a single field at most focal lengths. M82's hydrogen-alpha outflow is one of the most striking details to target — glowing red filaments extending perpendicular to the galaxy's disk.
