Assessment of Night Sky Brightness and Light Pollution Around the UTM Observatory, Johor, Malaysia

Abstract

This study investigates the influence of artificial lighting on night sky brightness in the vicinity of the UTM Observatory, Johor, Malaysia.
Measurements were conducted using a Sky Quality Meter (SQM) at twelve locations representing different land-use environments, including
residential zones, road networks, commercial areas, and a stadium. Recorded values ranged from 16.66 to 19.07 mag/arcsec², indicating
noticeable spatial variation caused by surrounding artificial light sources. The brightest sky conditions (16.66 mag/arcsec²) were detected near
stadium floodlights, while the darkest measurements (19.07 mag/arcsec²) were obtained close to UTM Tropical Park, where artificial lighting
is limited. A statistical evaluation was performed to identify the dominant contributors to sky brightness degradation. Results indicate that the
observatory is exposed to moderate to high levels of light pollution relative to dark-sky standards, potentially reducing the visibility of celestial
objects and affecting astronomical observations. The findings highlight the need for targeted mitigation, particularly involving stadium and
roadway lighting, and provide baseline information for long-term monitoring and observatory protection.