We recorded our first spectrograms on comet Hale Bopp with a wood spectrometer on a HP5 film only because of its exceptional luminosity.
Now we have built a grating spectrograph (still in evolution - see the photo on the left) with CCD detector that allows us to measure the red shift of galaxies and to record spectra with resolution better than 1 Å on stars brighter than 9th magnitude.
We are more and more fascinated from astronomical spectroscopy for the possibility of experiencing a wide range of astrophysical problems:
cosmological red-shift, stellar shells and atmospheres, chemical abundancies, electronic pressures, temperature of white dwarfs,
physico-chemical conditions in comets and outer planets, discovery of double stars, and many more …
But any amateur astronomer that approaches spectroscopy without the possibility to access to professional astronomical observatory’s
libraries and experience meets a lot of difficulties in achieving information on what to expect to see in a spectrum, why certain lines appear,
which element produces them, why they are enlarged or shifted or how to build or find something …It is for that that I would like to share my
results with the ambition that this internet address became a forum (and thus your contributions are welcome) for all those who want to engage
in the discovery of astronomical spectroscopy.
Paolo Valisa
(p_valisa -at- virgilio.it)