The Veil Nebula is a supernova remnant found in the Cygnus constellation. There are several names and catalog identifiers for various parts of this nebula complex, and I won't list them all here.

More information about this object can be found on its Wikipedia page.

A supernova remnant is the leftover cloud of gas that results from the explosion of a star in a supernova. It normally has a complex structure which is sculpted by the shock wave of the explosion, and the ejected stellar material can be accelerated to velocities as high as 10% of light speed.

The mix of red and blue colours in this nebula are the result of the mixture of hydrogen and oxygen (as well as many other elements that don't contribute as much to the visible appearance of the nebula) being stimulated to emit their characteristic wavelengths of light, i.e. red light from the hydrogen and blue-green light from the oxygen.

You can view this image in the WorldWideTelescope by clicking here.