SH2-240 (Simeis 147 ) This nebula which is a supernova remnant is a very large object and requires a large field of view; the nebula goes beyond the image seen here. Sh2-240 is also very faint so any telescope you use will need a long exposure. The nebula responds very well with the hydrogen-alpha filter but you need a lot of exposure time to colorize the nebula. This object was so large it required a two mosaic image with a large format camera. A large telescope will not capture the entire object but can pick up the very fine detail and deep structure the object is famous for. For a complete list of the Sharpless Catalog visit my main site at http://www.sharplesscatalog.com