Veil Nebular Complex

The Veil Nebular Complex is a group of nebulas situated at the external border of the Swan constellation.
Its main components are NGC 6960 (on the right side of the picture, surrounding the bright star 12 Cygni), NGC 6992 (on the left) and Pickering's triangle (on the upper side, pointing downwards).
The chromatich contrast between red and blue regions highlights the difference in contentration of hydrogen and oxygen gases.