The bright 3rd magnitude stars μ (left) and η (right) Geminorum frame this image.
On the right side of the image lies IC 443, also known as the Jellyfish Nebula or Sharpless 248 (Sh2-248). It is a galactic supernova remnant (SNR) and lies approximately 5,000 light years away from Earth. The nebula is named after its distinctive shape, which resembles a jellyfish swimming through space. IC 443 has a shell-like appearance, consisting of two connected sub-shells with different centers and radii. It spans an angular diameter of 50 arcminutes (larger than the full moon) which corresponds to a physical size of roughly 70 light years. IC 443 is the aftermath of a massive star that exploded as a supernova. This event likely occurred 30,000 - 35,000 years ago. The remnants include a collapsed stellar core, which is now a neutron star, which emits X-rays.
Slightly above the image's center, you can find a third sub-shell outside of the other two shells. It was initially attributed to IC 443, but is now recognized as a different and older SNR designated G189.6+3.3.
On the left side of the image, the emission nebula Sh2-249 includes the star μ Geminorum and extends to the north. It is about 5,200 light years distance from Earth.
The fourth nebula visible in this image is IC 444 near upper edge and a little bit to the right. IC 444 is a small, 32 square arcminute mixed emission and reflection nebula.
Gemini, zoom lens photograph.
IC 443 - Jellyfish Nebula, Wide Field in Hα, which is part of this image.
IC 443 - Jellyfish Nebula, Newtonian CCD-image.
Exposure Data
