Prototype 1.25 inch filter cell grating - Supernova sn2005cf 7-8 June 2005

The SC3 "PIPCAM" modified webcam was used with the VC200L at approx f5 for this image.

The combination of low altitude (25deg) and summer twilight and the low brightness at mag +13.5 made the spectrum difficult to record.

By using an IR blocking filter to reduce interference from the sky background and combining 300 20sec exposures taken over two days a faint image was obtained.

The resulting spectrum was very noisy and has been smoothed. The small scale variations may be noise, but the absence of a strong H alpha line is as expected for a type Ia supernova. (compare with the spectrum of a type II supernova sn2004dj )