BandungBergerak.id – Bandung Institute of Technology (ITB) held a big celebration to commemorate a century of the establishment of the Bosscha Observatory on January 30, 2023. In the book Seabad Observatorium Bosscha 1923-2023: Pengembangan Astronomi Modern di Indonesia, which was distributed specifically as an event book for the 100th anniversary of the Bosscha Observatory, the Secretary of the Institute, Prof. Widjaja Martokusumo, said that the commemoration event held that day at the observatory complex in Lembang, West Bandung, was part of a series of events to celebrate 100 years of the Bosscha Observatory which will be held throughout 2023. Part of the commemoration series included the issuance of special stamps with Bosscha Observatory images by Perum Peruri and PT POS Indonesia.

In the program book, ITB Rector Prof. Reini Wirahadikusumah quoted a little story of Bosscha Observatory. "I can only presume and imagine what the leaders of related universities were thinking when in 1951 FIPIA University of Indonesia (which later became FMIPA Bandung Institute of Technology) received the Bosscha Observatory which was handed over by NISV to the Indonesian Government through the Ministry of Education, Teaching, and Culture," she said.

ITB chose January 1, 1923 as the date of the Bosscha Observatory's establishment. In the program book, Dean of FMIPA ITB Prof. Wahyu Srigutomo mentioned that the date was the inauguration date of the observatory which was founded on the initiative of K.A.R Bosscha and the Nederlandsch-Indische Sterrenkundige Vereeniging. "Then Bosscha Observatory became part of the Bandung Institute of Technology (ITB) since 1951," he said.

Baca Juga: NGULIK BANDUNG: Blue Whale van Garut
NGULIK BANDUNG: The Expressway between Bandung and Batavia

Nederlandsch-Indische Sterrenkundige Vereeniging

The celebration held by ITB is indeed worthy to commemorate the long journey of the observatory that has contributed a lot to research in astronomy because of its strategic location because it is located in the southern hemisphere as well as very close to the earth's equator line. In its day, only a few large observatories were established in the southern hemisphere.

De locomotief newspaper of November 9, 1920 quoted Dutch astronomer Prof. Dr. H.G. van de Sande Bakhuyzen at a meeting of the Koninklijke Akademie (Royal Academy) in charge of mathematics and natural sciences in Amsterdam about the strategic plan to establish an observatory in the Dutch East Indies. Strategically located in the southern hemisphere.

Observatories in the Netherlands, especially the research they produce, have to compete with hundreds of observatories that are geographically located in the northern hemisphere. While in the southern hemisphere, there are at least three large observatories, namely in Cape Town in Africa, Cordoba in South America, and Australia. The lack of observatories in the southern hemisphere means that astronomical research resulting from observations of celestial objects in the southern sky is still limited. The Dutch East Indies is located on the equator, making the location of observatories there even more strategic for astronomical observations. Van de Sande Bakhuyzen, at the meeting, also supported the plan to establish an observatory in the Dutch East Indies proposed by the Nederlandsch-Indische Sterrenkundige Vereeniging (NISV) or the Dutch East Indies Astronomical Society.

NISV was an organization that gathered individuals who were not government officials in the Dutch East Indies who had an interest in astronomy. NISV has only one goal, namely to establish an observatory in the Dutch East Indies. De locomotief newspaper (November 9, 1920) mentioned that the NISV had even received approval from astronomers from various countries to realize this plan. Among them are support from Prof. J.C. Kapteyn, Prof. H. G. van de Sande Bakhuyzen, Prof. de Sitter, Prof. Hertzsprung, Prof. Lorentz, Prof. Nijland, Prof. G. Hale from Mount Wilson Observatory, Prof. Fr. Schlesinger of Yale University, Prof. H. N. Russel of Princeton University. The support was due to the importance of observations of the southern sky which are still rare due to the limited number of observatories located in the southern hemisphere.

The initiator of the establishment of the NISV was the Administrator of the Malabar Tea Plantation in Preanger, Dutch East Indies, Karel Albert Rudolf Bosscha. The landlord on the slopes of the Malabar mountains was the most insistent in the plan to establish the observatory. De Preanger-bode newspaper dated July 8, 1920 tells how insistent Bosscha is in pushing for the establishment of the observatory, promising to build an observatory that will be the largest observatory in the southern hemisphere. For the sake of his ambition, Bosscha deliberately consulted Prof. J. C. Kapteyn, director of the astronomy laboratory in Groningen and professors W. de Sitter and Hertzsprung, respectively director and deputy director of the observatory in Leiden.

Until finally Bosscha with his strong network gathered the wealthy in Bandung to establish the NISV. De Preanger-bode newspaper dated September 13, 1920 tells the story of the meeting that took place at the Homman Hotel Bandung, the day before. Starting with forming a small committee until the NISV board was elected which was announced on September 12, 1920 at a meeting at the hotel.

K.A.R. Bosscha, chairman, Zeilinga (Javasche Bank), Van Houten (Factorij), Wesselink (K.P.M.), Dr. Braak (Kon. Natuurk. Vereen.). M.H. Damme (Insulinde). Prof. Klopper (Rect. Magn. Techn. Hoogeschool), R. Neumann (Baroe Adjak farming company, donor of the site in Lembang), Secretary R. A. Kerkhoven (Adm, Malabar), "wrote De Preanger-bode (September 13, 1920) detailing the core NISV board.

At the meeting Bosscha promised to get a telescope that would be the largest telescope in observatories in the southern earth with a telescope focal length of 8-10 meters. For comparison, the focal length of the star telescope at that time was in South Africa with a focal length of 7 meters. It was pictured at the meeting that the giant telescope would be housed in a giant dome building. A rough estimate of the cost required to build it exceeded one hundred thousand gulden.

The location of the observatory building has also been chosen, on the highest hill on the southern slope of Mount Tangkuban Parahu. The land was donated by the Baroe Adjak Livestock Company in Lembang. The company promised to provide up to 3.5 hectares of land.

Donations from members of the newly formed association were also collected at the meeting. Prof. H.G. van de Sande Bakhuizen promised to send his collection of books in the astronomy library in the Netherlands for the observatory, Mr. Tan from Batavia donated f 1,000, Mr. Tan from Bandung donated f 500, and Mr. N donated f 1,000.

The NISV agreed to remain open to accepting new members. Of course, those who want to join must pay dues as proof of support for the big plan to build the largest observatory in the southern hemisphere. The founders who participated in the meeting were obliged to make a donation of 10 thousand gulden. Then every year, including those who joined later paid 100-500 gulden per year, plus membership fees of 10 gulden per year.

Onnen Critique

The ambitious plan immediately sparked enthusiasm from many parties. This included criticism expressed openly through newspapers.

De locomotief newspaper dated November 10, 1920 published an open letter from M.F. Onnen, a businessman living in Semarang. In the open letter, Onnen opposed the choice of Bandung as the location for the observatory. He argued that Bandung was not the right place because it was not located exactly on the earth’s equator. The most suitable location is exactly on the equator line. He proposed two locations that should be considered instead of Bandung, either one of the mountain peaks near Padang, or looking for high hills near Pontianak.

"What are the advantages of an observatory at the equator, apart from those already mentioned, that no stars, comets, etc. can escape observation," Onnen wrote in the De locomotief newspaper on November 10, 1920.

De locomotief newspaper was the most vocal in criticizing the plan to build observatory in Bandung. The newspaper wrote in its November 11, 1920 issue that there was already one observatory close to the equator, and the observatory in Bandung would only be the second. The observatory was located slightly below the equator in Quito, Ecuador, at an altitude of 2,850m.

As if he got the chance, Onnen criticized again in an open letter published in the newspaper De locomotief on November 12, 1920. "The promoters of the Dutch East Indies observatory have the opportunity to achieve something special and worthy by placing Bosscha's giant telescope on the equator, and not right next to it," he wrote.

The NISV answered the criticism. It was the Secretary and also the Treasurer of the NISV, R.A. Kerkhoven, who sent an open letter published in the newspaper De locomotief on November 25, 1920. He conveyed the association's decision to continue the plan to establish the observatory in Lembang, Bandung. The following is an excerpt from Kerkhoven's letter. 

"In theory, Mr. Onnen is correct when he says that one can only survey the entire starry sky from the equator, but practice shows that one cannot make precise astronomical observations below an altitude of about 300°. Close to the horizon, whereas the poles lie in the mind's array, the disturbing atmospheric influences are the strongest. As a result, the observing area in the sky is limited to a strip about 60° wide on either side of the Zenith, i.e., for any observatory located between latitude 30° north and latitude 30° south, both poles are invisible to precise measurements from the astronomer's point of view. This is the case both at the equator and at Lembang, and moreover, nowhere in the world can one point to a place where one can make serious observations stretching across the entire starry sky.

But this is also not necessary. We can safely leave the Northern Hemisphere to observatories in Europe and America, and the area around the South Pole to Cape Town and Sydney. But there are still vast stretches of sky that are most favorable to us, and which will give us a wide field of activity for an indefinite period of time."

The NISV's plan to build a giant observatory seemed to be going smoothly. The Deli courant of November 30, 1920 reported on the rapid development of the plan. The newspaper described that the observatory would have at least two main buildings. One building with a large dome, and another building similar to the dome but smaller in size.

The exact location is on land owned by the Baroe Adjak Farm. The dome building will top the highest hill on the land.

The architectural firm Schoemaker en Associatie was commissioned to design the observatory building. “The dome itself was sent from Europe, only the lower structure was made here," wrote the Deli courant on November 30, 1920.

* Translated from this article by Khumaira Birru Al Walidain.