Big scope peers into the depths of our spiral arms

Abell 20 is a faint planetary nebula in Canis Minor near Monoceros, which is nearly as wide from our perspective as the beautiful Ring nebula in Lyra. The main difference is that this one is about magnitude 14.7, nearly 6 magnitudes fainter and only 1/200 th as bright! It needs a hefty telescope like our 20” to help gather and capture its elusive photons, most of which are a delightful turquoise shade of doubly-ionised oxygen. The central star looks quite busy but only appears so from our distant vantage point. It is magnitude 16.5. Apologies for what looks like green rain falling diagonally across the picture. It is an artefact of some detrailing I did and the over-processing required to see the “faint fuzzy”.