<p><strong>Abstrak: </strong>Ulama-ulama Nusantara telah memainkan peranan bagi penguatan dan pelestarian khazanah keilmuan Islam di Nusantara, termasuk dalam bidang ilmu falak, dan ironinya tidak banyak kajian yang dilakukan para ahli terhadap karya-karya akademik mereka dalam bidang ini. Artikel ini akan mengkaji kontribusi Syaikh Hasan Maksum seorang mufti Kesultanan Deli yang sangat berpengaruh di Sumatera Timur. Seperti halnya ulama-ulama Nusantara lainnya, ia pernah belajar di Haramain (Makkah dan Madinah) dalam waktu yang cukup lama. Secara khusus, artikel ini akan mengulas karyanya yang berjudul <em>Natîjah Abadiyah</em><em>,</em><em> </em>dengan menggunakan analisis isi. <em>Natîjah Abadiyah</em> (natijah abadi) adalah buku yang sangat ringkas namun sangat penting, yang berisi daftar dan penjelasan tentang waktu-waktu salat.<br /> <strong></strong></p><p><strong>Kata Kunci:</strong><em><strong> </strong></em>Nusantara, Sumatera Timur, ilmu falak, waktu salat, Hasan Maksum<br /> <strong></strong></p><p><strong>Abstract: The Study of Astronomy in Indonesia: Shaykh Hasan Maksum’s Contribution to Astronomy.</strong> Islamic scholars have played a role for the strengthening and preservation of Islamic scholarship in Indonesia, including in Astronomy. Unfortunately, works on this field have not been studied accordingly. This article examines the contribution of Shaykh Hasan Maksum, a very influential mufti on Deli sultanate in East Sumatra. Like many other Nusantara scholars, he studied in Haramain (Makkah and Madinah) for a substantial time. This article studies his work, <em>Natîjah Abadiyah, </em>applying Content Analysis. It is clear that the <em>Natijah Abadiyah </em>is a short yet very important for it contains daily prayer timetable and some necessary explanations.<br /> <br /><strong>Keywords:</strong> Indonesia Archipelago, East Sumatera, Astronomy, time of prayer, Hasan Maksum</p>

Astrotourism is a tourist activity that shows attractions in the form of astronomical phenomena and outer space. Astrotourism activities that can be carried out by tourists are such as studying and exploring astronomical phenomena such as eclipses, meteor showers, and so on in the conditions of the night sky. An important condition for the advancement of astrotourism in an area is that the area has dark skies that are characterized by no severe light pollution and had adequate atmospheric conditions such as at least clouds covering the sky so that celestial objects can be observed properly, temperature, humidity, wind speed. and good rainfall so that visitors or tourists can comfortably be at astronomical tourist sites for a long time. We’ve done collecting atmospheric data using portable weather station and sky brightness data using Unihedron Sky Quality Meter LU-DL type device from July 10th - 11th 2021 and we collected data from windy.com for atmospheric particle content and cloud coverage during those dates. The results showed that Barus can become a new potential astrotourism destination specifically in Northern Sumatera or broadly in Indonesia where the Light pollution in Barus city is quite low, with a maximum value of brightness sky of 21.6, 20.8, and 21.8 MPSAS for the east, zenith, and west directions, respectively; Atmospheric conditions are quite good with an average temperature of 25.9 °C, the humidity of 89.2%, wind speed of 2.07 km/h, rainfall of 33.1 mm, amount of particles in the atmosphere 0.13 AOD and heat index of 27.2 °C Future study is needed from other aspects to make Barus become a new astrotourism destination in Indonesia.

<p><strong>Abstrak:</strong> Studi ini mengkaji perkembangan ilmu falak di Nusantara. Perkembangan studi falak memang relatif tertinggal jauh dari perkembangannya di pusat-pusat peradaban Islam seperti Damaskus, Baghdad, Kairo dan Cordova. Ilmu falak baru berkembang di Kepulauan Nusantara sejak abad 19-20 M. Penulisan karya-karya ilmu falak oleh ulama Nusantara abad 19-20 pun lebih didasari oleh pemenuhan kebutuhan ibadah sehari-hari, khususnya salat dan puasa. Dalam konteks ini, penggambaran historiografi dan transmisi perkembangan ilmu falak dari Timur Tengah ke Nusantara masih terhitung sebagai kajian terlantar. Karena itu, diperlukan kajian komprehensif tentang perkembangan studi ilmu falak di Indonesia. Sebagai studi awal, artikel ini merupakan hasil penelitian kepustakaan dengan pendekatan sejarah dimana datanya didasarkan pada telaah dokumen. Kajian ini mengemukakan bahwa ilmu falak mulai berkembang di Nusantara mulai abad ke-19, dimana para ulama Nusantara mendalami ilmu tersebut dari Timur Tengah dengan ragam motivasi, dan kemudian mereka mengembangkannya di tanah kelahiran dan mewariskan sejumlah karya dalam bidang ini.</p><p><strong>Abstract: Historiography of the Science of Astronomy in Indonesian Archipelago: History, Motivation and Early Figures</strong>. This study examines the development of astronomy in Indonesian archipelago which was relatively left behind by its development in the centers of Islamic civilization such as Damascus, Baghdad, Cairo and Cordova. As a matter of fact, astronomy did not develop in the Archipelago until in the 19th and 20th centuries, when some works on the field were identified. These works of the 19th and 20th century scholars mostly fulfilled the needs of daily worship, especially prayer and fasting. The historiography of astronomy in Indonesia and its transmission from the Middle East present an interesting field of research that has not been. The present article is a result of a preliminary library research focusing on history, motivation, and the early scholars of the field. Apparently, local scholars studied astronomy in different seats of knowledge in the Middle East and then brought it home. In order to meet local need they authored several books on the field which need to be be studied further in the coming years.</p><p><strong>Kata Kunci:</strong> astronomi, ulama, Nusantara, Timur Tengah</p>

Penelitian ini merupakan penelitian eksperimental yang dilakukan dengan tujuan untuk mengukur secara tidak langsung diameter dan kedalaman kawah bulan yang diperoleh saat pengamatan Bulan. Penelitian ini dilakukan di Observatorium Ilmu falak Universitas Muhammadiyah Sumatera Utara  dengan menggunakan teleskop William Optics Gt 102, Mounting iEQ45 Pro Kamera CCD QHY 5-II dan Canoon 600D. Penelitian ini fokus pada pengamatan kawah di Bulan, menentukan ukuran diameter dan kedalamannya pada basis foto dan perhitungan sederhana dengan beberapa penyederhanaan matematis. Berdasarkan hasil yang diperoleh dari penelitian, didapat nilai untuk diameter (d) dan kedalaman (h) untuk kawah bernama Tycho yaitu  d=102,95; h=6,6. Copernicus d=110,14; h=5,4. Schiller d=28,98; h=8,6. Kepler d=178,82; h=3,8 dengan tingkat kesalahan pengukuran 2%.