And now a lovely colour image of the strange low-surface brightness ionized oxygen nebulosity (the green-blue patch) right next to M31, the Andromeda galaxy, newly discovered by Marcel Drechsler et al.

Lots of interesting discussion below the image – they favour a location at the same distance as M31, although the scale & homogeneity of the structure does make me wonder whether it's much closer, in our galaxy.

https://www.astrobin.com/1d8ivk/

#astrodon #space #astronomy