This is a crop of a five panel mosaic of a elliptical galaxy: NGC 4278. Many background galaxies are also visible. In general, the fuzzier, more extended ones are background galaxies while the sharper, more point-like ones are globular clusters encircling NGC 4278. Interloping Milky Way stars are largely absent, but I think I see a few very dim ones.

There were some Chandra observations of NGC 4278 showing that several of the globular clusters are glowing in X-rays. chandra.harvard.edu/photo/2010/type1a/ (Yes, that's Andromeda. The picture of NGC 4283 can be found in the right side column)

The blank corners are the edges of the fields where no data is available.

Two HST proposals related to this image are available: Probing The Globular Cluster / Low Mass X-ray Binary Connection in Early-type Galaxies At Low X-ray Luminosities Probing The Globular Cluster / Low Mass X-ray Binary Connection in Early-type Galaxies At Low X-ray Luminosities

Yes, they both have the same title. The second finished up where the first left off. I think it got interrupted by the ACS's electrical problems. Good to be able to pick back up afterward thanks to some nice astronauts. You can see the noise stripes in the upper left field which started appearing after the mission which repaired the ACS. All the others were taken prior to Servicing Mission 4.

Red: ACS WFC F850LP Green: Pseudo Blue: ACS WFC F475W