title: UBVRI night sky brightness at Kottamia Astronomical Observatory
abstract: Photoelectric observations of night sky brightness (NSB) at different zenith distances and azimuths, covering all the sky, at the Egyptian Kottamia Astronomical observatory (KAO) site of coordinates ϕ = 29° 55.9' N and λ = 31° 49.5' E, were done using a fully automated photoelectric photometer (FAPP). The Bessel wide range system (UBVRI) is used for the first time to observe NSB for three consecutive nights (1-3 August, 2022) under good seeing conditions after the moon sets. The deduced results 
journal: Scientific Reports