A "tantalising veil" in motion - couple of frames four years apart are showing blast wave spreading in space away from supernova, in the region of eastern veil nebula. Images by HST.

I was planning to stack two images together when I've realized they are not the same.
There is also an object which appears like a star flying in sync with the wave, which could be a chunk of some material or just an accidental noisy blip. I've double checked my star alignment, it doesn't look like alignment error. Can you find it?

Image credits: NASA/ESA/Hubble
Processing & copyright: Leo Shatz

See also
[1] "A tantalising veil" https://spacetelescope.org/images/heic0006b
[2] Publication by William P. Blair from Johns Hopkins University compares two images of larger portion of the Veil Nebula http://heritage.stsci.edu/2015/29/images/Blair_Veil_notes-150922b.pdf