The Pinwheel Galaxy (M101, Messier 101,
or NGC 5457)
is a spiral galaxy about
22 million light-years' distant that is oriented
moderately close to perpendicular to the line of sight,
i.e., so the spiral is fully in view,
an advantage for its study.
It is classified as a grand design spiral galaxy,
i.e., showing a very clear spiral structure.
Recent Type Ia supernova, SN 2011fe,
was in M101.