| dimensions =11.2 x 6.9'<ref name=messier-objects>[http://www.messier-objects.com/messier-51-whirlpool-galaxy/ M51] from messier-objects.com</ref> | | dimensions =11.2 x 6.9'<ref name=messier-objects>[http://www.messier-objects.com/messier-51-whirlpool-galaxy/ M51] from messier-objects.com</ref> |