LBN 576 in H alpha - Oxygen III - RGB

LBN 576 (also known as Abell 85 and CTB 1) is a large supernova remnant in Cassiopeia.

It was initially catalogued by George Abell as a planetary nebula, but it soon became clear that it was an SNR. It was also recognized as a radio source and thus given the designation CTB 1.

LBN 576 is about 10000 light years away from us and is extremely faint. The Oxygen III content is very low, and lower than "usual" for this type of nebula.

Imaging it (and further processing) has been a challenge for me, and I am not sure if I have been able to show all the information I collected.

On the right you can see first the Hydrogen alpha image which accumulates 21 hours of exposure.

The second image is a Ha - OIII - RGB composition which accumulates near 52 hours of exposure.

Updated 20/05/2022

I took this image in autumn 2021 and when I presented it, as you can read above, I wrote:

“…and is extremely faint… Imaging it (and further processing) has been a challenge for me, and I am not sure if I have been able to show all the information I collected…”

With the processing skills acquired in my last images (NGC5907, Leo Triplet…), I have reprocessed it. The result is the third image on the right (that has been processed with Pixinsight 1.8.9.1).

The main improvements have been achieved by applying a two-part histogram stretch (using the GeneralisedHyperbolicStretch tool) and a better treatment of the large-scale components of the image.

Click on the images for a higher resolution version, or go to the Gallery section for complete exposure details.

Observatory automation and remote operation with Talon6