IC 443 (aka the Jellyfish Nebula or Sharpless 248 Sh2-248) is a galactic supernova remnant in Gemini. Its distance is roughly 5,000 light years from Earth.
IC 443 may be the remains of a supernova that occurred 3,000 – 30,000 years ago. The same supernova event likely created the neutron star CXOU J061705.3+222127, the collapsed remnant of the stellar core.
The dataset below has Ha and OIII (no SII) and I processed it with the Foraxx palette. RGB is also available for either a true color image or a narrow band/RGB mix.