Re: Spectral Analysis

"Nasty Gash" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> [EMAIL PROTECTED] (Nasty Gash) wrote in message
news:<[EMAIL PROTECTED]>...
> > What would be required to do spectral analysis of stars, nebulae and
> > galaxies with an 8 inch SCT?  What other equipment would be needed?
> > Anyone have links or other references?
> >
> > Thanks
>
> I should be a bit more specific...
>
> I'm interested in studying the spectra (IR to UV or wherever a CCD or
> vidicon is sensitive) of astronomical objects.  What would I need to
> build an inexpensive spectroscope that I could attach to my 8" SCT?
> Would this scope even collect enough photons to render a usable image?
>  Is the resolution of a digital camera's CCD fine enough to discern
> enough emission and absorption lines to make it worthwile?
>
> Any comments will be appreciated.
There are a couple of units on the market (for instance SBIG, sell their SGS
system). A review of this is in the May 2000 S&T. This is about $5000 (not
'inexpensive'...).
However there are a number of ways of making a spectroscope.
There are designs based on slit interference, ones based on reflective
interference (using a CD), and ones based on prisms. One design is at:
http://home.freeuk.net/m.gavin/mk1afocal.htm
Yes, a typical CCD, is 'fine enough'.
You might consider the book:
http://www.astunit.com/publications/4894.htm
The basic 'optics' (diffraction grating, or prism, and a collimating lens),
for a simple spectroscope, can be obtained from most optical suppliers, and
will not be too expensive. You'lll probably find that the spectrum is
limited by the glass in the optics of both the SCT, the specrometer itself,
and the sensitivity of the sensor. However operation across the entire
visible spectrum, and a short way beyond is quite possible.

Best Wishes