Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia  

作　　者：Mohammad Redzuan Tahar Farahana Kamarudin Roslan Umar Mohd Khairul Amri Kamarudin Nor Hazmin Sabri Karzaman Ahmad Sobri Abdul Rahim Mohd Sharul Aikal Baharim 

机构地区：[1]Langkawi National Observatory, Space Science Research Unit, National Space Agency, Empangan Bukit Malut, 07000, Langkawi, Kedah, Malaysia [2]East Coast Environmental Research Institute (ESERI), Universiti Sultan Zainal Abidin, Gong Badak Campus, 21300 Kuala Terengganu, Terengganu, Malaysia [3]School of Fundamental Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia [4]Department of Surveying Science and Geomatic, Faculty of Architecture, Planning and Surveying, Universiti Teknologi Mara, 02600 Arau, Perlis, Malaysia

出　　处：《Research in Astronomy and Astrophysics》2017年第4期57-66,共10页天文和天体物理学研究（英文版）

基　　金：Langkawi National Observatory,Space Science Research Unit,National Space Agency and East Coast Environmental Research Institute(ESERI);Universiti Sultan Zainal Abidin under university grant(RACE/F1/ST1/UNISZA/15-RR118)

摘　　要：Sky brightness is an essential topic in the field of astronomy, especially for optical astronom- ical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter （SQM） manu- factured by Unihedron are used to measure the sky brightness on a moonless night （or when the Moon is below the horizon）, when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System （GIS）, thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × 10-4cd m-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.Sky brightness is an essential topic in the field of astronomy, especially for optical astronom- ical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter （SQM） manu- factured by Unihedron are used to measure the sky brightness on a moonless night （or when the Moon is below the horizon）, when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System （GIS）, thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × 10-4cd m-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

关 键 词：light pollution - atlases - site testing - methods data analysis 

分 类 号：P12[天文地球—天体测量] X122[天文地球—天文学]