Abell 31 (Sharpless 2-290): finished!

Abell 31 (Sh2 290) is a large, faint, ancient planetary nebula located in the constellation of Cancer. It is estimated to be about 2000 light-years away from us.

It is one of the largest planetary nebulae in the sky and has a very low surface brightness.

I started imaging this nebula (back in 2012-2013!!) as an RGB image, but due to its low surface brightness I soon introduced Luminance data as well.

I was not able to process and present the (L)RGB image until 2020. The first image on the right is this image, with about 21 hours of accumulated exposure (obtained in person at my observatory).

This beginning of the year I have been able to accumulate much more exposure of this object, working in remote, with narrowband filters Ha and OIII.

The second image on the right is a HaR-OIIIG-OIIIB composition (with RGB stars) accumulating 57 hours of exposure.

It is reprocessed from scratch to take advantage of the improvements introduced in PixInsight in these two years.

Click on the image for a full size version, or go to the Gallery section for complete exposure details.