Messier 91 is a barred spiral galaxy located in the constellation Coma Berenices. It’s part of the Virgo Cluster of galaxies and is about 63 million light-years away from the Earth. It was the last of a group of eight nebulae discovered by Charles Messier in 1781. Originally, M91 was a missing object in the Messier catalogue as the result a bookkeeping mistake by Messier. It was not until 1969 that amateur astronomer William C. Williams realized that M91 was the galaxy that had also be cataloged as NGC 4548.
Image Credit: (CC) Joseph D. Schulman