Comet C/2012 E2 (SWAN), the official name for Comet SWAN, diving into the Sun as seen from the COR2A instrument of STEREO. (click to embiggen)
The Beacon images I posted earlier were from the behind spacecraft, but the high resolution fits from the behind spacecraft have not been posted yet.
I made an animation, see below. Comet Al has a nice multiframe image.
Animation of comet C/2012 SWAN sundiving in the COR2A instrument of STEREO.