The Jellyfish nebula is a mosaic of 2 Ha images of 15 and 10 frames of 1800 sec of exposition time for a total of 12 hr 30m with the FSQ telescope and the QHY90A CCD, taken in January 2017.
IC443 is a beautiful supernova remnant in the constellation Gemini, produced by a supernova explosion thought to have occurred about 30,000 years ago. X-ray emissions are produced by a neutron star hidden deep within the nebula, which is all that remains of the original star. The neutron star is highly dense and rapidly rotating, representing the end stage of a star with between 1.4 and 3 solar masses.
The cloud system on the upper left side of the image is a HII region known as S249. This area of the galactic plane is rich of interesting objects and therefore has been deeply studied in the last decades. For example the report “The Nature of the filaments Northeast of the SNR IC 443” deals with the filaments inside the rectangle in the image below, withdrawn from the report.
Many other information and references to work about IC443 can be obtained by the related SkyMap page.