Not everyone agrees that this object, also catalogued as
NGC 5866, should be identified as M 102. The controversy arose
because Messier received the report of a nebula discovery from
his friend Pierre Mechain, and Messier recorded it as number
102 in his list without the proper location. Many astronomers think
that M 102 is actually a duplicate "discovery" of M 101. However, NGC
5866 matches Messier's own notes about the object better.

M 102 is designated a "lenticular" galaxy, a flat disc galaxy that
lacks well-defined spiral arms. We see this galaxy nearly edge-on, and
on the full-sized version you can clearly see a lane of dust stretching across
the middle of the galaxy. Such dust is unusual, however, for a lenticular
galaxy, and so some have suggested that this is, in fact, a more typical
spiral galaxy. It is very difficult to distinguish the two kinds of galaxy
from an edge-on persective. If we could see the broad face of this galaxy,
we could tell whether it has defined arms (spiral) or not (lenticular).

Because of its shape, this galaxy is nicknamed "the spindle galaxy". It is in
the constellation Draco. It is 45 million light years away, and 69,000 light years
in diameter.

Image data:
Camera: Canon 350 XT (modified)
Exposure: ISO 800, 5 minutes x 21
Telescope: 10" Schmidt-Newtonian, Baader MPCC, LPS filter