The Cygnus loop can be found in the constellation Cygnus and is a supernova remnant. A supernova is a powerful and luminous explosion of a star and occurs at the end of its life cycle. In this case, the source star was approximately 20 times larger than our own sun. This source star exploded between 10'000 and 20'000 years ago. At the time, the explosion was so bright that it could be seen even during the day. The layers of this star can be seen today as nebulae. The entire remnant expanded over the years and now covers an area in the night sky about six times the diameter of the moon.

The remnant consists mainly of three distinct regions. The Eastern Veil Nebula at the bottom of the image, the Western Veil Nebula at the top of the image and Pickering's Triangle between these two.