NGC 6992, commonly known as the Eastern Veil Nebula, is the eastern component of the Veil Nebular Complex in the Swan constellation visible during summer. Its structure is packed with fine details easily observable in this picture shot at a medium focal length. This huge Nebular Complex is made up of NGC6992, NGC6960 and Pickering's Triangle (you can see a full picture of it here on my website).
The chromatic difference between red and blue regions reflect the different concentrations of the hydrogen (red) and oxygen (blue) gases that form this nebula.