The Pinwheel Galaxy is a face-on, unbarred, and counterclockwise spiral galaxy located 21 million light-years (6.4 megaparsecs) from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.

While I was working on this project, a star was discovered to have gone supernova inside one of the spiral arms of the Pinwheel Galaxy. I unintentionally captured this supernova (I was unaware of it's existence while shooting) in narrowband the night after it appeared. While it may not look like much -- it is just a point of light from our perspective -- it is such a thrill to be able to capture the light from a star exploding 21 million light years away onto a tiny electronic sensor that can turn those photons into not only scientific data, but cool pictures :)