It's a spiral in space created by a pair of stars enshrouded by dust. There are any number of circumstances that might obscure this structure. The stars could be oriented differently, making it impossible for us to make out the spiral. They could be moving in a different direction through space, making the spiral take on a different appearance. We could be in a different part of the galaxy, too distant to glimpse it.

Lucky us. We get a space spiral. It has no self-illumination in visible light, so it is being illuminated by the light from any nearby Mliky Way stars. The bright star does not necessarily have anything to do with the illumination even though it looks like it might.

This is one of my favorite things ever. I have tried to process it before, but couldn't do it any justice. I decided to take another look today and noticed there were some data available at MAST that weren't in the HLA back when I tried before. The longer exposures certainly help. I had to rotate the diffraction spikes for the F814W data to get them to match with the other two filters. There was a massive filter ghost I had to remove around the bright star.

As seen by the amazing ALMA: www.eso.org/public/images/potw1710a/

As described at spacetelescope.org: www.spacetelescope.org/images/potw1020a/

As described by Wikipedians: en.wikipedia.org/wiki/LL_Pegasi

Data from the following proposals were used: A Deep ACS Study of the Spiral Outflow from the Extreme Carbon Star, CRL3068 Are OH/IR stars the youngest post-AGB stars? An ACS SNAPshot imaging survey

Red: ACS/WFC F814W Green: ACS/WFC F606W Blue: ACS/WFC F475W