A recent New Scientist article suggests that the huge dark void (to left of galactic centre) in NGC 247 was caused by a direct hit from something invisible and heavy, such as a lump of dark matter. The collision triggered the birth of a ring of bright blue stars. 8 hours lum, 2hrs each RGB. Aspen 16M on PlaneWave 20". North down. Allergen advice: this image processed on sky visited by an asteroid, several satellites, and loose glare from Diphda. Traces may remain. Larger versions and other stuff at
http://mikeberthonjones.smugmug.com.