Ioannis wrote:
? "Abdul Ahad" ?????? ??? ??????
om...

What is the faintest "source" that can be spectroscopically analysed
via a telescope for fraunhofer lines and elemental composition?

I see no reason why it shouldn't be precisely the same magnitude
limit that exists for the larger scopes.

If it can be photographed, it can be spectrographed.

You're going to need a good few photons to be able to remove the
uncertainty as to peaks and troughs in the wavelength profile. In this
recent story:
http://www.astronomynow.com/news/040...t_galaxy.shtml
I imagine they had enough photons to calculate an approximate blackbody
curve to determine the redshift, but I very much doubt they could tell
you what the composition of the galaxy was!
--
Andrew Urquhart
Reply: www.andrewu.co.uk/about/contact/