Low dispersion spectrograph for weak objects

A slitless spectrograph in the kind of "The Spectrograph of the Observatory Leipzig" (see: "Zeitschrift für Instrumentenkunde", 55/1935; can be requested at group leader).

Collimator: f= -135mm (1:6)
Prism (Flint F2): 60°
Image optic: f = 58mm
Dispersion at Ha = 1785 Å/mm
R ~ 870

On 25. April 2000 I could win the spectrum of the Mira variable R Leonis (V=8mag) with 120 seconds  exposure only (see spectrum above) at a 20cm Schmidt-Cassegrain-telescope (f/4) in the observatory of Vereinigung der Sternfreunde Köln.

Despite the relatively small resolution the substantial spectral characteristics of the star, the absorption bands of the C2 and the TiO are to recognize satisfyingly.