Check out this new mid-infrared image of the Ring Nebula, taking with the MIRI instrument on the JWST! Stunning details visible in the surrounding shells. Credit: ESA/Webb, NASA, CSA, M. Barlow, N. Cox, R. Wesson

All signs seem to point to PAHs being responsible for the 2175Å extinction bump. Yet, it's really hard to get right with detailed modeling, as this paper shows. I feel like there's something fundamental we're missing, but I don't know what. https://arxiv.org/abs/2308.04084