Bubble Nebula in HOO

What you're looking at is the bubble nebula, a bubble in the sky that is formed by a massive, super-hot star blowing a cavity into surrounding gas and dust, probably the star is pre-supernova.

EXIF:

Camera: Nikon D3500 full spectrum
Filter: Svbony sv220
Lens: Sigma 400mm f5.6
Mount: iOptron skyguider pro
Tripod: Skywatcher tripod

420x30s iso 3200 f8

Stacked and processed in Siril and Photopea