IC443 nebula is also known as Jellyfish Nebula. It is supernova remnant (SNR) in the constellation Gemini placed about 5000 light years away. The nebula is quite large (almost as twice large as apparent Moon diameter) but glows very faint, and is difficult target for visual observing. The remnant’s age is still uncertain – different estimations give values between 3000 and 30000 years ago.
Shot with 8″ f/4 newtonian, Atik383 camera with hydrogen alpha and RGB filters, 5h50min total exposure time.