[O-08] Poster presentations by senior high school students

[O08-P74] A study of the light pollution using digital single-lens reflex camera and SQM

*Tatsuki Yoshihara¹, *Nanami Hiraoka¹, *Allysa Chiba¹, *Hinata Monma¹ (1.Tokyo metropolitan tachikawa high school)

Keywords:Brightness of the sky, light pollution, digital single-lens reflex camera

Using an automated digital single-lens reflex camera developed by the Astronomical Meteorological Department of our school, the researchers took regular photographs of changes in the brightness of the night sky for one year. This study is different from the conventional method of surveying the brightness of the night sky, which uses absolute values that measure the magnitude of celestial bodies. The researchers quantified the brightness of the night sky from a JPEG image, devised a new method to compare the difference in the brightness of the night sky and investigated it by season and time, and analyzed the factors. From the images taken by the camera, the researchers focused on the fact that the night sky becomes reddish when there are many clouds, and investigated the correlation between the RGB ratio of the brightness value of the night sky and the clouds. In addition, since the camera only captures very low altitudes in the horizontal direction, the researchers used SQM to investigate changes in the brightness of the night sky during night by the elevation angle and orientation.