220207 - Sh2-248 "Jellyfish" nebula
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click image to enlarge
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ASTRO:
type=Supernova remnant const=Gemini mag=12 dist=5000 ly size=70 ly IMAGE: location=EB Driveway BrtlCls=4 moon=58% (avg) WxCr exposure=DSLR OSC 41x600s (6.8h), ISO3200 EQUIPMENT: camera=Nikon D90 (mod) optics=ES102 w0.8x rdcr. eff. F=571mm, f/5.6 filter=Radian Triad Quad NB mount=Celestron AVX EQ guiding= Orion 60x240mm, ZWO ASi244MC SOFTWARE: acquisition=Stellarium, APT, PHD2 processing=DSS, PhotoshopCC, RCAstro, LrC |
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Sharpless 248 (also known as the Jellyfish Nebula, or IC 443) is a galactic supernova remnant (SNR) in the constellation Gemini. On the plane of the sky, it is located near the star Eta Geminorum. Its distance is roughly 5,000 light years from Earth.
The Jellyfish may be the remains of a supernova that occurred appx 16,000 years ago. The same supernova event likely created the neutron star that is the collapsed remnant of a stellar core inside the Jellyfish. It is one of the best-studied cases of a supernova remnant that is interacting with surrounding molecular clouds.
NASA's WISE (Wide-field Infrared Survey Explorer) spacecraft - an infrared-wavelength astronomical space telescope active from 2009 to 2011, and the predecessor to NEOWISE, a re-purposing of the space telescope for cometary reconnaissance - captured an image of the Jellyfish that provided an extended understanding of the nebula. It has an angular diameter of 50 arcmin (by comparison, the full moon is 30 arcmin across). At the estimated distance of 5,000 ly from Earth, it corresponds to a physical size of roughly 70 light years across its widest dimension.
Notably, the Jellyfish's X-ray morphology is centrally peaked. It is believed there may have actually been two (2) supernovas that occurred in this region of space. The SNR optical and radio morphology is shell-like, consisting of two connected sub-shells with different centers and radii. A third, larger sub-shell is now recognized as a different and older SNR (by appx 100,000 years).
Jellyfish's age is still uncertain. There is some agreement that the more prominent supernova happened appx 16,000 years ago. Recent Chandra and XMM-Newton observations identified a plerion nebula, close to the remnant southern rim. The point source near the northern apex of the nebula is a neutron star, the remaining relic of the SN explosion. The nebula's location inside a star forming region, and the presence of a neutron star indicate it is a Type II supernova, being the ultimate fate of a massive star explosion.
The Jellyfish may be the remains of a supernova that occurred appx 16,000 years ago. The same supernova event likely created the neutron star that is the collapsed remnant of a stellar core inside the Jellyfish. It is one of the best-studied cases of a supernova remnant that is interacting with surrounding molecular clouds.
NASA's WISE (Wide-field Infrared Survey Explorer) spacecraft - an infrared-wavelength astronomical space telescope active from 2009 to 2011, and the predecessor to NEOWISE, a re-purposing of the space telescope for cometary reconnaissance - captured an image of the Jellyfish that provided an extended understanding of the nebula. It has an angular diameter of 50 arcmin (by comparison, the full moon is 30 arcmin across). At the estimated distance of 5,000 ly from Earth, it corresponds to a physical size of roughly 70 light years across its widest dimension.
Notably, the Jellyfish's X-ray morphology is centrally peaked. It is believed there may have actually been two (2) supernovas that occurred in this region of space. The SNR optical and radio morphology is shell-like, consisting of two connected sub-shells with different centers and radii. A third, larger sub-shell is now recognized as a different and older SNR (by appx 100,000 years).
Jellyfish's age is still uncertain. There is some agreement that the more prominent supernova happened appx 16,000 years ago. Recent Chandra and XMM-Newton observations identified a plerion nebula, close to the remnant southern rim. The point source near the northern apex of the nebula is a neutron star, the remaining relic of the SN explosion. The nebula's location inside a star forming region, and the presence of a neutron star indicate it is a Type II supernova, being the ultimate fate of a massive star explosion.