I started capturing NGC 40 & CTA 1 almost three months ago between both my telescope rigs and am just finishing now. Between an unusually extra rainy summer here in Michigan, we also dealt with a lot of forest fire smoke; just like most of the U.S. this summer. I had to throw out a lot of bad data due to those smokey hazy nights. NGC 40 is a small but bright planetary nebula not too far from Polaris. What is not so bright is CTA 1; a big super nova remnant. Even though I pounded it with a lot of integration time, I still had to push the CTA 1 supernova remnant rather hard in processing. Because I pushed CTA 1 so hard, I had a lot of mottling of which I had to do a couple tricks to help mitigate that. 

NGC 40 is a bright planetary nebula consisting of a detailed core with an outer halo. This halo consists of a double structure with a diffuse inner halo attached to the central shell and a more irregular filamentary structure, which extends to the north. In addition to these array of features is a structure to the south, which has been interpreted as a jet. Professional observations with the Spitzer infrared telescope have shown the inner halo to consist of multiple overlapping radial spoke ring structures. This halo was discovered in 1987.

The central star of this planetary nebula has been well studied by professional astronomers and is also interesting in its own right. It belongs to the Wolf Rayet subclass of planetary nebula central stars that are hydrogen deficient and exhibit high mass loss rates and strong stellar winds. WR type central stars have been identified in a number of other planetary nebulae including IC 4663 and Abell 48.

Extending along the contours of the full field of this image are multiple colourful filaments belonging to the large faint supernova remnant CTA 1, which covers an area of 1.5 degrees across the sky. Both NGC 40 and CTA 1 are physically unrelated with the supernova remnant lying more distant in the background. NGC 40 is 3500 light years away and CTA 1 is 4500 light years away.