Visual measurements and spectral survey of night sky brightness in Venezuela and Italy

¹ Centro de Investigaciones de Astronomía CIDA, A.P. 264, 5101-A Mérida, Venezuela
² Dipartimento di Fisica, Università di Siena, Via Banchi di Sotto, 55 - 53100 Siena, Italy

Send offprint request to: F. Della Prugna

Received: 28 May 1999
Accepted: 9 September 1999

Abstract

This paper reports measurements of zenith night sky brightness and a spectral survey carried out at selected places in Venezuela and Italy. These range from large cities (Caracas and Florence) and towns (Mérida and Siena), to dark sites, such as the Venezuelan Astronomical Observatory and the Alps. Measurements were carried out visually by means of a simple photometer and spectra from 4100 to 6400 Å, were obtained by a small spectrograph. From the results obtained at the sites tested in Italy, the sky brightness increase since 1973 is given. Since in both countries there are effective regulations to fight light pollution, and more are foreseen in the near future, it is the purpose of this paper to stress the importance, and also the need, of night sky quality monitoring over time to assess the efficacy of these legal tools.