Alpy + `DIY` fibre spectro comparison

[Gasman]

Hi

Managed in between clouds tonight to try out the fibre optic spectrometer on my scope. Alpy 600 attached to my 120mm refractor  2secs exposure using a 600l/mm grating, spectrometer attached to my 80mm refractor 5000ms exposure . I was wrong about the software not allowing longer exposures, Spectrum Studio calls it `integration` and you get between 50millisecs and 65000millisecs. Object was Betelgeuse!

The Alpy spectrum (bottom) cropped the same as the spectrometer one from about 5200 angstroms to 6700 angstroms

Getting the star on the fibre was not easy at all and I`m not sure it really is worth the hassle but first attempt and I`ll try a few more times before deciding to pursue it

Cheers

Steve

[jnp]

Hi Steve,

You setup looks most impressive   

Are the 2 charts are of the same part of the Betelguese spectrum? Although the fire optic device spikes line up with the humps of the Alpy, I would have expected to see more of a continuum on the fire optic spectrum? It would be great if you could possibly try this on say the H alpha or Beta line of a A class star so we have a well defined feature to compare?  

Can you export the data out 'Spectrum studio' into FIT, Excel or text format?

regards

John

[Gasman]

Hi John

I agree, a good Halpha line would have been interesting to try but the visibility was very iffy and the law of sod appeared with my power pack running out and both scopes dewing over :-( even got dew inside both scopes behind the lenses, never had that before !

The data from the software is in .csv format. You get no fancy spectrum just a profile. I have an idea to use thicker core fibre as the one I'm using must be approximately 0.5 mm diameter so a PITA to get a star on it. I even thought of defocusing the star slightly to make the disc bigger to get it on the fibre, all trial and error at the moment. It also doesn't help having to hold the device as the fibre is only 0.5m long.

Steve