Bosscha Observatory Total Solar Eclipse Expedition: From Kisar Island for Indonesia

By Adi Permana

Editor Adi Permana

BANDUNG, itb.ac.id – Bosscha Observatory expedition team successfully carried out a total solar eclipse observation on Maka Field, Kisar Selatan District, Southwest Maluku Regency on Thursday (20/4/2023). The observation of this rare phenomenon was broadcasted live on Bosscha Observatory YouTube channel so that it can be witnessed by Indonesian who do not have the chance to observe it directly.

Kisar Island was chosen as the observation location for several reasons. Firstly, Kisar Island is the first island in Indonesia to be traversed by the eclipse totality.

The second reason is Kisar Island’s geographical location that is close to the center of the eclipse, which is the Timor Sea. The closer a place to the eclipse center, the longer it will be traversed by the eclipse totality.

Third, according to a cloud fraction cover study by ITB researchers, it was shown that Kisar Island has minimal cloud cover compared to other areas.

Solar eclipse observation on Kisar Island was optimal thanks to clear weather this morning. First contact of the solar eclipse happened on 11.47 GMT+9 and reached its totality on 13.22. During the totality phase which lasted 8 seconds, local residents witnessed a unique phenomenon which only lasted briefly.

“Moments leading up to the totality were very brief. So before the sun was 100% covered, there were unique phenomena that can be observed, but it was very brief,” explained Yatni Yulianti, a researcher from the Bosscha Observatory who presented the solar eclipse observation broadcast.

Phenomena such as Baily’s beads happened a mere seconds before the totality. Baily’s beads happened because the sun’s rays that were blocked by the moon managed to pass through the moon's uneven surface. When the moon has fully covered the sun, the remaining Baily’s beads will converge with the sun's corona and create a shape that resembles a light ring, this phenomenon is called diamond ring.

Then when the peak of totality is achieved, the sun’s corona will be the main spotlight because this phenomenon can only be observed during a total solar eclipse. If lucky, the solar prominence phenomenon can also be observed right after the totality phase.

As an educational and research institute, Bosscha Observatory transforms this solar eclipse moment into an opportunity to promote education. This was realized through various education programs for the public, both carried out directly by teams from Bosscha Observatory and through eclipse ambassadors throughout Indonesia.

“In this observation expedition, we received massive support from regional and central government, corporations, and our home institute. Education is the most important aspect, we spent a lot of time, so that we can turn this moment into a way to promote sustainable education, not only during an eclipse,” said Dr. Premana W. Premadi who led the expedition to Kisar Island.

Reporter: Hanifa Juliana (City and Regional Planning, 2020)
Translator: Favian Aldilla R (Civil Engineering, 2019)