2001 January 7 - spectra taken of Aldebaran, Betelgeuse, Procyon, Sirius to a dispersion of 0.25A/pixel via 300mm fl lens + 1200 l/mm grating + MX9 [11um pixels] show an improvement in quality by the removal of the x2 Barlow lens used in the previous spectra in this series. The grating is now fully illuminated at f/10 greatly improving the S/N ratio.
2001 January 2 - these experimental spectra taken over the Christmas/ New Year holiday period with the WPO spectrograph pumped-up to the highest dispersion yet achieved of 0.13A/pixel via 600mm fl lens and 1200 l/mm grating i.e. x10 the dispersion of the standard WPO spectrograph [using 58mm lens + 1200 l/mm grating] or x8 the dispersion of the SBIG spectrograph [using a 150mm fl Ebert mirror + 600 l/mm grating]. The full swath of spectrum is only 100A or about 1/10th of the standard WPO set-up.
However the standard f/10 beam projected via the LX200 into the spectrograph is vignetted by the effective f/ratio set by the grating size and lens combo to f/20. Thus only a fifth of the light entering the scope [allowing for secondary obstruction] is used in these promising results.
No slit was used - the spectra are the simple dispersion of sharp stellar images formed by the LX200 SCT but only lines common to both spectra [below] are real due to poor S/N ratio. However a fair match for Aldebaran and Pollux - both late type K spectra stars.
