Selama satu tahun, Matahari tidak selalu berada di daerah khatulistiwa, namun terkadang berada di daerah utara khatulistiwa serta daerah selatan khatulistiwa. Kedudukan Matahari di khatulistiwa disebut ekuinoks, kedudukan Matahari saat berada di titik terjauh di utara dari khatulistiwa disebut solstis musim panas (summer solstice), kedudukan Matahari saat berada di titik terjauh di selatan dari khatulistiwa disebut solstis musim dingin (winter solstice). Matahari di Observatorium Ilmu Falak Universitas Muhammadiyah Sumatera Utara menunjukkan posisi yang berbeda saat ekuinoks, summer soltice, dan winter solstice. Matahari terbit di arah timur dan terbenam di arah barat hanya terjadi pada saat ekuinoks. Meskipun saat ekuinoks, namun Matahari tidak dapat menunjukk arah timur dan barat sepanjang hari. Hal ini disebabkan pergerakan Matahari tidak tegak lurus terhadap horizon melainkan miring sesuai dengan lintang tempat.

The existence of technology, especially optics and digital, that can be used with similar settings anywhere so it can be implemented by anyone and become a new standard for the determination and visual view of early dawn time seen in the field. Digital cameras could take periodically so that they can produce a series of images according to time and show the difference in the sky when the transition of dawn time and be an option for the beginning of dawn time in the world evidentiary. The results of this study showed that there was a difference at the beginning of dawn time according to the Ministry of Religion with the results of processed imagery using the MA method. The results of the imagery successfully showed the beginning of the change in the sky at dawn with the appearance of a significant change in pixel value. This study found that the initial results of dawn time on the observation date were at the time of the sun at a dip of -17° 07' 12". The observations using SQM with data processing using the MA method also gave the same results as image processing from DSLR cameras

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.

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%.