Evidence of a supernova remnant in the Large Magellanic Cloud. Apparently the leading edge of an otherwise invisible (in these wavelengths) bubble expanding outward and colliding with some gas, which causes that gas to glow nicely.
I've long thought this one of the strangest patches of glowing gas. Every once in a while I see the image almost at random, and I always pause for it. Decided to process it myself just to stare at it some more. Looks like a balloon popped in space.
Data from the following proposals were used to create this image:
Orange: F673N WFPC2/WF
Cyan: F656N WFPC2/WF
Blue: F502N WFPC2/WF
North is NOT up. It is 40.2° clockwise from up.