I’ve been fascinated by Barnards Loop ever since I first saw a photo of it- an emission nebula that covers a huge part of the sky. In case you’re not familiar, it’s a large loop of gas centred roughly on Messier 42 that encircles good chunk of the Orion constellation. It’s thought to be a remnant of a Supernova from a couple of million years ago at least 100 light years across. I had a go at imaging it last year, but wasn’t especially thrilled with the results, so definitely on the list for another go. Easier said than done when you’re fighting light pollution…
I started this on 16th initially with an IDAS light pollution filter and a Sigma 18-55 lens. Unfortunately the lens/filter combination produced some very strange effects, so I took the filter out and stacked 20 minutes worth of data from 40x 30 second shots. I’m to the North of Burton and so Orion goes right over the light dome from the town- not a pretty sight:
I attacked it in Pixinsight with DBE. It’s a good tool, but the mess left behind from this one had me needing to clip the background out to get something presentable. Still- I thought it’d make a good base to mix some Ha over:
Next clear night was Christmas Eve. I waited for Orion to get nice and high in the sky and then had a go with a 7nm Baader Ha filter, collecting an hour of data. This really underlines how much LP gets generated by an average urban area. Despite around 95% of the visible spectrum being cut out, there’s still a pretty nasty gradient:
Did my best to sort it out, but it was still a pretty noisy image. Final result is below. If I want to get a decent version of this I think I’m going to need to go somewhere darker, but if anyone has any bright ideas for improving this in the meantime, I’m listening!