Cold Fuzz

I’ve heard about it, but I never thought it could happen to me. That’s right … I’m talking about thermal noise. I’ve been out in the cold lately and I’ve noticed that my new CCD has been very noisy. I thought I was doing something wrong (not configuring the software correctly etc.) but I now realize that my $99 CCD does have its limitations. I’m sure those CCD’s costing $1500 probably have similar problems, but hopefully this issue will be less pronounced once the weather warms up.

Thursday night was gorgeous. Cold, dark (with no stupid moon blinding me) and no wind. So I decided to take another crack at the Orion nebula. I took about 60 images that look about like this … pretty crappy, I know.

Then I thought hey, let’s grab a few dark frames that might help explain a few things. Here one such frame. You can really see that it ain’t dark, even with the lens cap on. I suspect much of the noise along the bottom is from heat or the nuclear radiation from the CCD electronics.

At this point, maybe I should mention again that Registax totally rocks. Take 60 crappy images of a fuzzy cloud that keeps bouncing around because of my $300 telescope and then load in the “dark” frame as a flat frame, let it make some pretty graphs for a few minutes, then you get this masterpiece. You can almost make out the whispery blue arms of the nebula just above and to the left of the central pair of stars. Click on the picture to see a more detailed version. Very cool. This technique deserves more experimenting.

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