Multispectral analysis of the night sky brightness and its origin for the Asiago Observatory, Italy

Night protection has been a major concern for astronomers since the electrification of cities and is beginning to be recognized as a major environmental problem. In recent years, regulations have been put in place through the establishment of Dark Sky Reserves that impose stringent constraints on lighting practices for cities in protected areas. Astronomers from the Asiago Observatory, located in the Veneto region of Italy, would like to create an area of this nature around their facilities to improve and protect the quality of their astronomical observations. This study assesses the current state of the sky in the region through numerical modelling using the latest improvements to the ILLUMINA model and aims to identify the main contributing sources of artificial light. The explicit calculation of the contribution of private residential lighting helps to discern the origin of the light. We also present a new approach for extracting an estimate of the distribution of lamp technology in a region from images taken from the International Space Station.