- A home-made anti-dewing system
- Can I detect a 14th-magnitude comet using a 70mm 'scope?
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I can talk about (and maybe demonstrate) a couple of things which I've been working on recently:
Well, as I explained last night, it was more like 15th magnitude.rwilkinson wrote:I can talk about.. a 14th-magnitude comet..
Then after I got home from the meeting I could see that the constellation of Auriga had risen above the trees, so I was able to have a go at it from my garden, using my preferred comet-imaging kit (an old StarlightXpress camera on my focal-reduced 8" SCT): This is a rather better result that I'd managed last week with the 70mm 'scope - so the gain of the longer exposures and larger optical system outweighed the increased light-pollution (and my LPR filter) plus the hazy cloud which came over during my imaging (so I had to omit some of the sequence from my stack - hence the gaps in the star-trails).
If anyone would like to make one of their own, this is a source of the "Heat-trace" cable:rwilkinson wrote:I can talk about.. a home-made anti-dewing system
http://www.ebay.co.uk/itm/12w-m-TRACE-H ... 0986887824
and the power-controllers which I mentioned:
http://www.ebay.co.uk/itm/DC-12V-8A-LED ... 2161210561
And here's a previous discussion with references to Constantan and Nichrome wires: