ATIK Cameras TITAN Quick Start Manual page 19

From Wikipedia: "The Triangulum Galaxy (also known as
Messier 33 or NGC 598) is a spiral galaxy approximately 3
million light-years away in the constellation Triangulum. The
galaxy is also sometimes informally referred to as the Pin-
wheel Galaxy by some amateur astronomy references and in
some public outreach websites."
Image by Paulo Bénard Guedes (Atik 16HR)