I know I’ve been going for faint targets, but this one has taken 7 or 8 attempts and exposing various equipment flaws that have shown up along the way. When I finalise the stack of 30 or 40 images, I still see nothing. Possibly a few grainy speckles appear on stretching the contrast. I had to combine 2 or 3 sets of stacks, and keep blurring, brightening, adjusting the variation in the background. It was virtually a month’s project and rather futile really, as there are some much better pictures, with much better equipment out there. Why do I do it? Because I can, and I enjoy persevering with the equipment to see what it can achieve. This thing is so big and faint that it is 0.4% brighter than the overhead light pollution background level (SQM reading averages 21.0). It’s probably even less than that at the altitude I took it at… and I cannot get a decent flat field image! So, all things considered, it might look a bit ugly, but it’s a monster. A strange, old monster that’s dissipating slowly into space. Search for it under PK219+31.1 or Abell 31 (details: 12.2m/17’x16’ – that’s big).
Tuesday, 19 April 2011
Abell 31
I know I’ve been going for faint targets, but this one has taken 7 or 8 attempts and exposing various equipment flaws that have shown up along the way. When I finalise the stack of 30 or 40 images, I still see nothing. Possibly a few grainy speckles appear on stretching the contrast. I had to combine 2 or 3 sets of stacks, and keep blurring, brightening, adjusting the variation in the background. It was virtually a month’s project and rather futile really, as there are some much better pictures, with much better equipment out there. Why do I do it? Because I can, and I enjoy persevering with the equipment to see what it can achieve. This thing is so big and faint that it is 0.4% brighter than the overhead light pollution background level (SQM reading averages 21.0). It’s probably even less than that at the altitude I took it at… and I cannot get a decent flat field image! So, all things considered, it might look a bit ugly, but it’s a monster. A strange, old monster that’s dissipating slowly into space. Search for it under PK219+31.1 or Abell 31 (details: 12.2m/17’x16’ – that’s big).
No comments:
Post a Comment