Development student guidebook on night sky brightness measurement project with DIY photometer kit

Abstract Night sky brightness (NSB) measurement is one of the activities carried out to determine the quality of the night sky in a place, and this value is very useful for observers of night sky objects. The more celestial objects, from the brightest to the faintest, be it stars, galaxies, nebulae, and so on, that can be seen indicates the quality of the night sky in that location is excellent. In addition, by measuring NSB, many things can be known, namely, twilight events, night length, and dawn events. One of the techniques used to make NSB measurements is a tool called a photometer. The limitations of specific photometer tools for NSB measurements have been answered by the availability of an independent or Do It Yourself (DIY) photometer that has been validated. The next problem is that there is still no guidebook for using the DIY photometer to guide students in making measurements. The purpose of this research is an effort to provide the utilization of DIY photometers in learning activities related to photometry, which went through the stages of validation by experts, respondents, and trials. The validation process of stage 1 of the initial product using the Aiken V Index by material experts, it was found that 68.7% had high validity and 31.3% had moderate validity from 16 validity indicators and by media experts, 66.7% were obtained in the high validity category and 33.3% had moderate validity from 18 validity indicators, in stage 2 validation by respondents, a total of 11 indicators were obtained in the valid. The stage 3 trial process, the percentage of product effectiveness was 87.5% with very high criteria and 12.5% with high criteria. The guidebook developed is suitable for use as a guide for using the DIY Photometer Kit for various learning and research purposes.