This is the dolphin head nebula, Cataloged Sharpless SH 2-308, it is about 5,200 light-years from home towards the constellation of the Big Dog.
The massive star (Wolf-Rayet type) that created the bubble is the bright star located near the center of the nebula.
It generates a powerful radiation which drives out the gas around thus creating a giant bubble.
To fully appreciate the details, here is the link: https://www.astrobin.com/full/zinhcg/0/
Technical details :
• TS 102mm F5,1 apo astrograph bezel
• Azeq6gt mount
• Zwo asi 1600 mm cooled pro
• Sampling: 1.47 arcsec / pixel.
• 93x300s O3 astronomik 6nm or 7 h 45 min
• 27x3x60s RGB ZWO or 1h 21 min
• Full integration: 9 h 6 min.
• DOF: 15x101x0
• Date: January 1 and 2, 2020
• Location: MAO Observatory of Ben Slimane.
