Light pollution at Bosscha Observatory, Indonesia

Abstract

To know the level of light pollution due to human activities, we performed sky brightness measurements at Bosscha Observatory, Indonesia (107°36E; 6°49'S, 1300 m above the sea level) during years 2011-2012 by using a portable photometer at zenith direction. From 400 records of night, we obtained that average and maximum sky brightness were 17.75±0.86 mag/arcsec sq. and 19.14±0.79 mag/arcsec sq., respectively. Cities around the Observatory, that are Bandung and Lembang, clearly give a strong contribution to light pollution. The patches of Milky Way galaxy are disappearing from the sky. Higher maximum sky brightness occurred after midnight. Brightness values before midnight were 17.83±0.83 mag/arcsec sq. on average and 18.98±0.78 mag/arcsec sq. at maximum, with average temperature of 18.8±1.3 C. The average and maximum magnitudes after midnight were 17.67±0.88 mag/arcsec sq. and 19.41±1.24 mag/arcsec sq. with average temperature of 17.1±1.6 C. Sky brightness depends on Moon age and monthly seasonal variations, but it has no relation with Earth eccentricity.