CTA 1 is a rarely imaged faint supernova remnant in constellation Cepheus about 4’600 light years from earth.

It is pretty large in the sky having a diameter of three times the moon. Therefore this image shows only a part of the expanding bubble of debris of a star which exploded about 10‘000 years ago in a violent supernova explosion. The core of the star collapsed to a neutron star which seems to be a gamma ray pulsar. The pulsar is however not active in the radio frequency range.
Embedded in this nebula we find the pretty bright but very small planetary nebula NGC 40, also called the Bow Tie Nebula. It is little bit closer, about 3’500 light years from earth and much younger. The progenitor star died about 4‘500 years ago and blew its outer shells quietly into space. It is visible left of the center of the image.
A close-up of NGC 40 will follow with some more information on this unusual planetary nebula.

Borg 90FL
1.08 Flattener
ZWO OAG
ASI 2600MM Pro
ZWO EFW
Baader Ultra-Narrowband 3.5/4nm, RGB Broadband
H: 36x300s
OIII: 36x300s
SII: 32x300s
R: 20x120s
G: 20x120s
B: 20x120s
Total Integration: 10h 40m
Bortle 4-5

PixInsight