Finally got to shoot the Dolphin Head Nebula, SH2-308! Been on my bucket list for the 3 years I've been into astrophotograpahy. Its somewhat difficult target for us up north, as its rather low in the sky in Canis Majoris, only the cold winter months when weather is usually bad can I capture it, and only high enough in the sky to shoot it for 1-2hrs each side of its transit. Additionally, I have a lot of light pollution low to the ground in my south, shooting towards a major city (though I'm ~B4 locally). I decided on shooting this with my more basic dslr/tracker rig while my telescope+GEM was shooting other objects. It might not compete with a big scope and mono cam but I still very much enjoy seeing what I can get with it. I captured 300" subs with NBZ duoband filter for 2 nights mid December, and had to wait another month for a clear night to capture proper color stars (just UV/IR cut filter). I would have liked to capture a lot more data but with the bad winter weather I'm going to call it done for now.

Sh2-308 surrounds the Wolf–Rayet star EZ Canis Majoris or EZ CMa. This star is in the brief, pre-supernova phase of its stellar evolution. The nebula was formed about 70,000 years ago by the star EZ Canis Majoris throwing off its outer hydrogen layers, revealing inner layers of heavier elements. Fast stellar winds create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of the star's evolution. I've always found it odd that all descriptions of this nebula indicate ionized hydrogen, yet in AP it seems to be mostly teal OIII emission that are captured, with hints of H-alpha signal here and there. Most descriptions don't even mention OIII emission at all. So weird!

Trivia: The Netflix sci-fi show Another Life (Katee Sackhoff) took place in this constellation. Much of the show was based around the star pi Canis Majoris, just outside of my framing. One or two other stars in Canis Majoris are in the show, one going supernova or something I can't quite remember.