Saturday 22 August 2009

The Helix Nebula

Contrary to what I've seen written, the Helix nebula is not the closest planetary nebula to us. It is one of my favourite objects but it is quite elusive, as it can only been seen at certain times under good conditions from UK and I had a good window of opportunity the other night. I took several shots, about 60 in all I think, 45 of which were good enough to stack (22x30",22x15" + 1'). The main trouble is that the nebula is so diffuse, it was barely visible on the individual pictures because of LIGHT POLLUTION! The worst culprits round here seem to be rural industry and carelessly aimed, wasteful and unnecessary security lights. So, to combat this, I stuck in a 40mm eyepiece on the 20" (60x) with a Lumicon UHC filter screwed on and the detail in the helix's structure was amazing and the centre of the nebula was filled in with a cool blue glow. I've done a lot of careful processing on the final image, as the flat fields were not as flat as I'd have liked (I took them on a white door indoors). It still looks quite noisy I think, but it's a beautiful object that I've been waiting a long while to photograph this well.

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