About image NGC 40 is a planetary nebula visible in the constellation of Cepheus. Its magnitude is 12.3 and its apparent dimensions are 38 "x35". Its diameter is around one year light, and contains within it a white dwarf, to which the nebula is due, with a surface temperature of 90 000 K; this star with its strong stellar wind interacts with the nebula, deforming it until it assumes an irregular shape. Within a few tens of millennia, the nebula will disperse into the interstellar medium, leaving the central dwarf star free, which will also go out slowly in space. The distance from the Solar System is estimated at around 11,750 light years.
Technical data Optics Celestron C9.25 Edge HD f/10 Mount Losmandy G11 with Ovision worm and FS2 Camera Atik 4000 with Starlight Xpress filter wheel 5 positions Filters Baader Ha 7nm and OIII 8.5nm, 50.8 unmounted Guiding system OAG LB Astro Proxima and Lodestar Exposure details Ha 31x120" bin1 -15C OIII 21x120" bin1 -15C Total integration 1.7h Acquisition Maxim, PHD2 Processing Maxim, Photoshop CS5 SQM-L 18.6 Location Home terrace (Rescaldina, Italy) Date 3 September 2013