A weather driven, emergency location in northeast Italy provided the backdrop for this image. Taken with a ¾ moon it shows the power of ultra-narrowband imaging. A winter target, the Jellyfish Nebula, IC 443, is a huge supernova remnant in the constellation of Gemini. It is approximately 5000 ly distant and is roughly 70 ly in size. For this image the sulphur-II emission, which is very prominent in the “Jellyfish”, is colour-mapped to yellow, differentiating it strongly from the neighbouring hydrogen-alpha emission areas. A small oxygen-III area is visible on the edge of the “head”. The brightest/largest stars in the image are Mu and Eta Geminorum.
Celestron RASA 11″
10Micron GM1000 HPS
SIGMA fp (monochrome) / SIGMA fp L (colour)
H-alpha / O-III / S-II ultra-fast narrowband filters
20 x 4 min, ISO 1600, F2.2, 620mm