Kisar Island was chosen as an observation spot due to its geography and weather. As the first region in Indonesia that is 100% in the pathway of the eclipse while being close to its center in the Timor Sea, the totality time of the eclipse in Kisar Island is longer than other regions.

The team of 10 people consisting of Bosscha Observatory staff and students of the ITB Undergraduate Astronomy Study Program did a series of educational activities for local teachers and students. These activities include night sky observations and astronomy exhibitions open to the public.

"The total solar eclipse observation will be held at Maka Field, Wonreli Village,” Premana stated. “Our team has prepared various instruments to be used together with the communities for observation."

A solar eclipse occurs when the Sun, Moon, and Earth are in an inline position, resulting in the Moon's shadow falling on the lunar surface. In a hybrid solar eclipse, two solar eclipse phenomena occur at once; the eclipse begins as a Ring Solar Eclipse before shifting into a Total Solar Eclipse and ends with a Ring Solar Eclipse again. During the April 20, 2023 eclipse, the path of the total solar eclipse will cross over Indonesia.

The shadow of the Moon falling to the Earth's surface is an area 270 km wide, resulting in a narrow, elongated band of trajectories of the Total Solar Eclipse. Referring to the eclipse map, the total trajectory (100?lipse) will move from Western Australia to the Timor Sea, passing through Timor Island which is part of the Democratic State of Timor Leste.

Kisar Island (number 1) became the first land in Indonesia to pass through the path of totality. The Moon's shadow then moves past the Batumerah area (number 2), the Banda Sea, Karas Island Papua (number 3), the mountainous regions of West Papua, Roswar Island (number 4), and Biak (number 5), then ends in the North Pacific Sea.

Premana explained that Bosscha Observatory has been actively involved in solar eclipse observations that passed through the Dutch East Indies region since the early 20th century (in 1922, 1921, 1926) and continues to do so after Indonesia’s independence. As an educational and research institution under ITB, the observatory makes use of the solar eclipse as a gateway to introducing the study of astronomy to a wider audience.

Aside from carrying out the expedition, Bosscha Observatory will also hold other activities related to the solar eclipse of April 20, 2023, including its livestream observation, observation in Lembang, the launch of the Solar Eclipse Series Stamps, socialization of its pre-eclipse occurrence, and observation of Hilal Syawal 1444 H/2023.

Source: Obsevatorium Bosscha
Reporter: Adi Permana
Translator: Ruth Nathania (Environmental Engineering, 2019)