IC 443 (Jellyfish Nebula) · Seestar S30 · 2026-04-08
IC 443, nicknamed the Jellyfish Nebula, is a supernova remnant in the constellation Gemini, located near the star Eta Geminorum at the foot of the Twins.
Click on the image to open it at full resolution.
IC 443, nicknamed the Jellyfish Nebula, is a supernova remnant in the constellation Gemini, located near the star Eta Geminorum at the foot of the Twins. Estimates place it roughly 5,000 light-years away (with some studies suggesting closer to 6,000), giving it a true diameter on the order of 70 light-years; the explosion that created it likely occurred tens of thousands of years ago, though age estimates vary widely. The remnant is associated with a neutron star, and its shock front is seen colliding with adjacent molecular clouds, producing the tangled, tentacle-like filaments that give the nebula its name. Both Hα and O III narrowband filters are effective here, revealing the delicate shock-excited filaments against the surrounding star field, with the brighter western arc offering the most photogenic detail for amateur imagers.
