The Impact of Light Pollution on Islamic New Moon (hilal) Observation

Abstract

Muslims has differentiated between new moon and Islamic new moon (hilal). The determination of first day of months based on visibility of Islamic new moon (hilal) i.e. sightings of the first sliver of the waxing moon marking the start of each month. One major issue that has affected hilal visibility for many years is misdirected, excessive and obtrusive artificial light. The objective of this research is to study the impact of light pollution on the visibility of hilal. The data were taken using Sky Quality Meter (SQM) which records the visual magnitudes per square arcsecond (mpsas) to measure sky limiting magnitude. Result showed that reading between 16-22 mpsas, the chances to witness hilal is high. Any lower than 16mpsas, the hilal is not visible. The main result of this research is to find out a vital parameter of hilal observations which leads to propose a new criterion i.e. sky limiting magnitude.

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