NGC 5866 (also called the Spindle Galaxy or Messier 102) is a relatively bright lenticular galaxy in the constellation Draco. Measured orbital velocities of its globular cluster system imply that dark matter makes up only 34±45% of the mass within 5 effective radii; a notable paucity.
Distance: 50 million lightyears.
NGC 5866 is one of the brightest galaxies in the NGC 5866 Group, a small galaxy group that also includes the spiral galaxies NGC 5879 and NGC 5907. This group may actually be a subclump at the northwest end of a large, elongated structure that comprises the M51 Group and the M101 Group, although most sources distinguish the three groups as separate entities.