M91
For a long time, M91 was a missing Messier object, as Messier had determined its position from M89 while he thought it was from M58, as a Texas amateur figured out in 1969.
The barred spiral galaxy M91 is an appealing member of the Virgo Cluster of Galaxies. It is of type SBb and its bar is very conspicuous, lying at position angle 65/245 degrees (as measured from the North direction to the East). Suggestions of this bar may be seen at medium power even in smaller telescopes, if the viewing conditions are good enough to see the galaxy at all. As its recession velocity is only about 400 km/sec, it has a considerable peculiar velocity toward us through the Virgo cluster, about 700 km/sec, as the cluster's recession velocity is about 1100 km/sec.