SagDEG was until recently thought to be the nearest galaxy. [diameter 8x3 deg]
"Globular cluster
M54 coincides with one of the [SagDEG] galaxy's two bright knots, and is also receding at about the same velocity. It may also be at the same distance (about 88,000 light years), so probably M54 is the first "extragalactic" globular ever discovered ...
Because of the extreme intrinsic luminosity of M54 in comparison to the other globular clusters associated with SagDEG, it has been speculated early that M54 may be the nucleus of this dwarf galaxy, or the remnant of its nucleus (
Bassino and Muzzio, 1995)..."
http://www.seds.org/messier/more/SagdEg.html
http://adsabs.harvard.edu/cgi-bin/np..._key=AST&high=