KONTRIBUSI SYAIKH MUHAMMAD THAHIR JALALUDDIN DALAM BIDANG ILMU FALAK

Abstrak: Fajar adalah fenomena alami yang terjadi disebabkan rotasi Bumi pada porosnya. Permasalahan awal waktu fajar senantiasa menjadi kajian baik di kalangan fukaha maupun ilmuwan Muslim. Di Indonesia, sejak lama berlaku ketetapan dip-20 derajat di bawah ufuk dalam penentuan waktu Subuh. Ketentuan ini berasal dari pendapat Syaikh Muhammad Thahir Jalaluddin (w. 1376/1956) dalam karyanya Nukhbah al-Taqrîrât fi Hisâb al-Auqât. Makalah ini akan menelusuri pemikiran Syaikh Muhammad Thahir Jalaluddin tentang hal ini melalui karyanya tersebut dalam merumuskan konsepsi 20 derajat ini. Melalui analisis dan penelusuran sejumlah literatur, ditemukan bahwa dip -20 derajat ini ternyata dihasilkan hanya berdasarkan nukilan dari karya dan atau pemikiran tokoh-tokoh sebelumnya baik tokoh Nusantara maupun tokoh yang bermukim di Haramain, khususnya melalui kitab al-Mathla‘ al-Sa‘îd karya Husain Zaid Mesir.Abstract: Shaykh Muhammad Thahir Jalaluddin’s Contribution in Islamic Astronomy. This article studies on the early dawn time and its influence on the determination dawn in Indonesia. Dawn is a natural phenomenon that can be seen while the earth rotates on its axis. The issue of the beginning of dawn has become a heated debate both within the Indonesian Muslim scholars (fuqaha) and scientists alike. In Indonesia, to determine dawn prayer’s time has been set up dip -20 degree below the horizon. This determination was adopted from Muhammad Thahir Jalaluddin’s idea in his work Nukhbah al-Taqrîrât fi Hisâb al-Auqât. This paper is trying to explore Muhammad Thahir Jalaluddin’s thought concerning the issue through his work which formulated this conception of 20 degree. In this article, the author found that after a thorough and critical analysis of some important literature and references, it is concluded that this conception was strictly quoted from other works and other previous Muslim scholars idea who lived in Haramain, especially in the book al-Mathla‘ al-Sa‘îd which was written out by Husain Zaid Mishr.Kata Kunci: Muhammad Thahir Jalaluddin, waktu fajar, Nusantara, astronomi