Looking at the sky with a digital spectrophotometer

Paola La Rocca and Francesco Riggi

Department of Physics and Astronomy, University of Catania, Catania (Italy)

Digital spectrophotometers allow a variety of educational measurements of emission and absorption spectra of light sources. As an example we report the observation of the skylight under different conditions, showing both the most prominent absorption Fraunhofer lines and the slight differences which can be observed in the spectral composition of the light for different orientations and time during the day. The measurements can be carried out with a simple digital spectrophotometer - now available at a reasonable cost - as an educational activity for college or undergraduate physics students.