Sh2-123, as designated in the Sharpless Catalog of HII regions, is a somewhat obscure and very faint nebula that is not often imaged by amateur astronomers. Perhaps this is due to its faintness. It is evident in hydrogen alpha (Ha) filtered images. This Ha data was blended into the visible red channel in order to bring out the contour and details displayed in the above image. Due to the object's shape, it is sometimes referred to as the "flea" nebula. It is located approximately 12,000 lightyears distance in the constellation Cygnus the Swan.