Sharpless 308 (Sh 2-308), commonly known as the Dolphin-Head Nebula, is an H II region located near the center of the constellation Canis Major, composed of ionised hydrogen.
The nebula is about 4,530 light-years away and approximately 60 light-years across at its widest point.   It has an apparent magnitude of 6.91  and  about 35' x +35' arcminutes in size. The nebula's bubble surrounds a Wolf–Rayet star named EZ Canis Majoris which is in the brief, pre-supernova phase of its stellar evolution. When it goes bang this will all be past tense.

This was a bit of an adventure as I normally never go beyond 10 minutes exposures; for this I used 30 minute exposures collected over 5 nights from 4th to 20th February with conditions varying from very challenging to really excellent seeing. Summer can be like that.  Dodging heat,  cloud, rain and hail only to have the heavens open up in all too brief moments of glory. The observatory was pushing 35 degrees in the day so I put in a small Wi-Fi controlled sprinkler on the roof which helps as beyond 36 degrees, I would need to pack the gear away. It never really cooled down properly at night.  I took every window of opportunity to grab a few more subs as I wanted to get at least 8 for every filter, as required to get drizzle to co-operate. Miraculously, there was one brief star link satellite in the corner of one image, and the mount only went into recovery mode once with some low cloud (which can be very annoying when shooting 30 minutes exposures) ,  so time to buy a lottery ticket! 

Thus, with 12 hours of useable data in hand, the Pixinsight bag of tricks was rolled out. The downside of long exposures is dealing with the star brightness.
StarXTerminator just gives up on some  of the brighter ones, but Bill Blanshan's Star Reduction pixel math scripts came in very handy taming the background tumult.

It's time to move on and get back to 5 minute exposures and maybe a nice summer galaxy in RGB, weather permitting.