IC 443. The Jellyfish Nebula

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IC 443, also called the Jellyfish Nebula or Sh2-248 is a supernova remnant (SNR) located about 1,500 light years away in the constellation Gemini. This is the remains of a powerful blast that occurred between 3,000 and 30,000 years ago, but most probably around 10,000 years ago. The pulsar that was formed during the supernova explosion, CXOU J061705.3+222127, is a bright X-Ray source, but faint in visible light emission. It is not visible in this image. IC 443 is not the only SNR present in this image. The faint double arc visible at the upper left corner is a fragment of another SNR of a supernova that exploded about 100,000 years ago, G189.6+3.3. There is another SNR, close to the southern rim (North is directly up in this image), but just like IC 443’s pulsar, it emits mostly in X-Rays. The kind of SNRs, like this last one, powered only by the emission of their pulsars are called “plerions”, a paramount example of this type of nebulae is M1, the Crab Nebula. IC 443 is also interacting with the Hydrogen cloud that formed its progenitor star.


This image is a 2×2 mosaic taken with narrowband filters (Halpha and OIII) and color mapped to natural colors. No significant difference was found between the 3 nm bandpass Halpha and NII emissions, as it is the case with other SNRs. This way, the whole mosaic was taken with 5 nm bandpass Halpha filter.

Additional Information


Name(s): IC 443. Sh2-248. The Jellyfish Nebula

Type: Supernova Remnant

RA:  06h 16m 53s

Dec: +22º 46’ 55”

Constellation: Gemini

Size (arcmin): 50×40 arcmin

Magnitude: +12.0

Distance: 1,500 light years


Date: 2022-10-29 to 2023-01-11

Location: Curiosity2 Observatory, New Mexico Skies, Mayhill, NM, USA

Size (arcmin): 58×48 arcmin

Telescope: 24” (61 cm) f/6.5 Reflector

Camera: FLI PL16803 (4096x4096pix)

Guiding: Astrodon MonsterMOAG off-axis guider

Total exposure: 97 h 20 m (Ha:

Processing: CCDStack, PixInsight (one step) and Photoshop CC 2023


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