Caldwell 33, also known as NGC 6992, is the eastern part of the "Veil Nebula", a supernova remnant in the constellation of Cygnus. It lies at a distance of ~1,300 light-years.The first image comprises 15 x Luminance (45 seconds each) and 6 x Red, Green and Blue (60, 60 and 48 seconds each), 0.5m f/2.9 ASA Astrograph with FLI ML3200 camera at an altitude of 80 degrees on 3 July 2017. The field of view is 34’ x 23’.The second, third and fourth images comprise 5 x Ha, OIII and SII, all 300 seconds each with the 0.5m f/2.9 ASA Astrograph with FLI ML3200 camera at an altitude of 80 degrees on 27 June 2017. The fields of view of the images are 34’ x 23’. The first of these follows the HST convention, with cloours mapped as follows: SII-Ha-OIII mapped to RGB. The second shows the same frames presented using the CFHT convention, Ha-OIII-SII mapped to RGB. The final image is a monochrome composite.
Hills Observatory: 1 January 2013 to 8 October 2018