Flemming’s Triangular Wisp is part of a supernova remnant in the constellation Cygnus. It was discovered in 1904 by Williamina Fleming but was credited to Edward Pickering, the director of the observatory and so is commonly known as Pickering’s Triangle. The object is part of a larger Cygnus Loop which occupies about 36 times the area of the full moon. It is estimated to be about 2400 light years distant and was formed about 15000 years ago.
The narrow band image below is a bi-colour representation with Ha mapped to red and OIII mapped to green and blue. It represents 16 hours integration and was taken with my Esprit 150.