IC443, Jellyfish Nebula

March 2021

Imaging: ST120 achro, Canon 1000D 800 ISO, L-Enhance filter
Subs: 268x180s (13h), bias, darks, and flats
Processing: PixInsight

(Additional notes below)



The Jellyfish Nebula is a galactic supernova remnant (i.e. the remains of an exploded star), believed to have been created by a supernova explosion between 3000 to 30000 years ago. This supernova also created a neutron star which is the collapsed remnant of the exploded star's core. (A teaspoon of neutron star material weighs about a billion tons!) It may not be immediately obvious from my fuzzy picture but the undulating surface of the nebula certainly resembles a jellyfish body.

The photos that went into this image were captured over 5 nights in early March in a roughly south-western direction of the sky. I struggled with the post-processing for this one. The lower left part of the image is all messed up and I have no idea why. This is a rather long 13 hours of integration which should have produced a clean, low noise image. And it was using the L-Enhance filter which should have significantly reduced the light pollution. This just goes to show how much more I have to learn in this sometimes frustrating hobby.

Update: the "noise" in lower left is not noise at all! It turns out that this is some OIII that is supposed to be there. My camera doesn't quite capture the color and it is very faint so I assumed it was noise. Again... so much in this hobby to learn.