STUDI KECERLANGAN LANGIT TERHADAP VISIBILITAS HILAL

• Main Author: Puspita Arumaningtyas, Eka
• Format: Final Project
• Language: Indonesia
• Subjects: Astronomi
• Online Access: https://digilib.itb.ac.id/gdl/view/40942
• Institution: Institut Teknologi Bandung

First date of Hijriah calendar defined by the thin crescent is first visible after new moon. There are some methods for determining the visibility of the Moon. One common theme is apparent in all the methods. They are all measure of the minimum contrast required to observe the Moon (Hoofman 2002). The contrast is ratio of two components: the illuminance of the Moon and the brightness of the sky. The calculation of sky brightness was using the model derived by Schaefer (1993). However, the prediction of contrast was using different definitions such as Ilyas (1984), Schaefer (1993), and Sultan (2006). Result of the calculation show that the sky brightness proportional to the higher elevation and the altitude of the Moon and the Sun. However, the sky brightness was inversely proportional to the relative humidity and separation between sky direction and the Moon and the Sun. The sky brightness in winter solstice is higher than in summer solstice. The prediction of contrast using Ilyas and Sultan definition was inversely proportional to the sky brightness. However, the prediction of contrast using Schaefer definition was proportional to the sky brightness.