The evolution of the night sky spectrum in Asiago

In this work I analyze the spectral evolution of the night sky at the Asiago Observatory between 2006 and 2021. I developed an automatic pipeline to extract and analyze the background data from spectroscopic observation of astronomical objects. Sky spectra from Asiago are dominated by different artificial sources, which were studied in detail in this work. I conclude that between 2006 and 2021 mercury vapor lamps got duced by 88%, sodium ones by 67%. Between 2016 and 2021 emission from LED lamps increased by 207%. LED lamps continuum pollutes the blue band of the visible spectrum -- previously untouched by artificial emission -- and replaces HPS emission in the green-red bands, thus polluting the whole visible spectrum.