NGC 2359 Thor’s Helmet is an emission nebula with an ionized HII region in the constellation Canis Major.
NGC 2359 spans roughly 30 light-years across and appears as an interstellar bubble that has been inflated by a central Wolf-Rayet star.

This is a Bi-color Narrow Band Image. Ha data was taken on 15 March 2014 and OIII data was taken on 19 December 2020, both from Lockwood Valley, California

Ha 120 minutes 2x binned, 15 min sub-exposures
OIII 210 minutes 2x binned, 15 min sub-exposures

Total Exposure Time = 5 hours 30 min