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Supernova Remnant SNR G116.9+0.2, also known as CTB 1


SNR G116.9+0.2, also known as CTB 1

Object name
SNR G116.9+0.2, also known as CTB 1

Constellation: Cassiopeia
Distance: 3600 light years

Imaged by Jean-Yves Beninger from Alqueva Dark Sky, Portugal
On 29 June, 2, 3, 4, 5, 13 and 14 July 2025

Equipment:
Astro-Physics Mach1
Astro-Physics AP130 Starfire EDF with 2.7" field flattener 67PF562, 873mm
Camera Zwo ASI 2600MM pixel size 3.76µ
Filters H, O, R, G, B

HOO image with RGB stars

Description:

SNR G116.9+0.2, also known as CTB 1, is a supernova remnant located in the constellation Cassiopeia, around 10,000 light-years away from Earth. It's the aftermath of a massive star's explosive death—an event that occurred tens of thousands of years ago.

What makes CTB 1 particularly fascinating is its shell-like structure. The remnant forms a roughly circular bubble of energized gas and magnetic fields, about 100 light-years in diameter, slowly expanding into the interstellar medium.

CTB 1 is categorized as a mixed-morphology supernova remnant, meaning it shows a radio-bright outer shell and X-ray emission from its interior. This combination suggests interactions with surrounding dense clouds and the presence of hot plasma trapped inside the remnant.

Researchers believe CTB 1 may have been formed by a core-collapse supernova, and there is evidence of a neutron star or pulsar left behind—an incredibly dense, spinning remnant of the original star's core.

CTB-1 was initially classified as an unidentified radio source in the 1960 CTB catalogue by Wilson and Bolton, which listed supernova remnants and other radio sources within the Galactic plane.