View Full Version here: : T Pyx spectrum, 23 Apr 2011
23-04-2011, 11:35 PM
Hmmm, now this is rough but I'm pretty happy with it under the circumstances really. Shot at 200mm tonight using Star Analyser, but had awful trouble with dew on the grating. Still, this shot shows emissions at the main hydrogen lines, H-alpha, H-Beta & H-Gamma.
This is a loooong strip so click it to full size! :thumbsup:
24-04-2011, 12:15 AM
Well done Rob.
24-04-2011, 10:06 PM
What exposure times??
You could clean it up under IRIS and sky background removal to get maximum detail out of it under Vspec... worth trying.
25-04-2011, 12:41 AM
Thanks Terry, Ken! This was 8 x 2min, Canon 400D @ 200mm, ISO 1600, F/5.6. That is the flat-out limit of what I can do (camera wide-open, maximum feasible exposure time), other than more subs of course. I did have a bit of a play with VSpec and got the three spikes but it wasn't very pretty. Ken, I'll have to find time and have a good read of your book, as well as the VSpec manual.
This was really just a bit of an experiment, to see whether with very limited gear I could detect the signature Balmer line emissions of a fairly bright nova. To that extent, I'm happy with the result. It kind of fits (no, not FITS :lol: ) with the known & potential RN monitoring I'm doing, along with a pretty basic nova search. Pity I didn't have T Pyx on my list, dammit! :P But great work by Michael Linnolt, shows that the system can work.
25-04-2011, 01:23 AM
As the filter is only 25mm aperture, you're working close to f8,
at 200mm the spectrum zero to red is only 14.0mm, the total spectrum being 6.4mm in length, but the plate scale is much better than you'd get normally sitting the grating at 60mm in the telescope.
More subs would definately help.
Janet S. had had good success with her 350D and a 85mm lens recording some interesting WR spectra.
Use IRIS to convert to fits and background removal then over to Vspec...
Onwards and upwards.
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