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A story-studded sky

National Observatory completes 180 years of service and research

National Observatory

Great Equatorial Dome, in 1880, installed in the National Observatory on the Castelo hill. It no longer exists.National Observatory

Consider the following approximate dates: 30 years ago, the observations to define the Sun’s diameter began; 40 years ago, cesium-133 atomic clocks were adopted to measure the time in Brazil more precisely; 50 years ago, a magnetic observatory was set up on the island of Tatuoca, in an estuary on the River Amazon, to expand the study of geomagnetism and monitor the Earth’s magnetic field. Apart from ephemerides, only an institution such as the National Observatory (NO), which was responsible for the aforementioned elements, could have a history as rich and extensive. The quality of the work it has conducted and its longevity provide us with a goodly number of dates full of achievements to celebrate. In October one more memorable date will occur: the observatory will celebrate its 180th anniversary.

The National Observatory is one of Brazil’s oldest scientific institutions. Established by Emperor Pedro I in 1827, it is the oldest observatory still operating in the Southern Hemisphere and it was devised for strategic reasons. The royal family had been in this country since 1808 and it was necessary to find out more about Brazilian geography, define its borders, and gather and disseminate reliable navigational information. The NO’s origins, however, go back a full century before this time. “In 1730, according to the priest Serafim Leite, the Jesuits installed an observatory on Castelo hill, in Rio de Janeiro”, explains Marcomede Rangel, a physicist at the NO and a student of its history. Portuguese astronomers Sanches d’Orta and Oliveira Barbosa set up an observatory in this place in 1780, in order to conduct regular astronomy observations. The collection they put together was transferred to the Royal Military Academy in 1808.

In the book O observatório astronômico: um século de história 1827-1927 (The astronomical observatory: one centry of history – 1827-1927) (Mast/Salamandra, 1987), Henrique Charles Morize, an astronomer and former NO director, explains how urgent it was to obtain scientific data about the country as a geographical reference covering both land and sea: “Ship captains need to know the magnetic inclination, as well as the mean time and the longitude, in order to adjust their chronometers, to be able to safely undertake a return journey or to continue the current one”. Ship captains or those in charge of navigation did this based on approximate calculations. “But this could be obtained more precisely and easily by professionals equipped with instruments, in an observatory”, wrote Morize.

The first observatory was set up in the tower of the Military School, under the coordination of Pedro de Alcântara Bellegarde, a Mathematics professor, and was called the Astronomical Observatory, linked to the Ministry of the Empire. Actually, this institution had other names until it was given its current one, in 1920. After almost two decades, the minister of War, Jerônimo Francisco Coelho, reorganized it in 1845 and appointed as its director professor Soulier de Sauvre, from the Military School, who provided it with its first set of governing rules.

“From 1827 to 1871, the observatory focused almost only on teaching the students of the land and naval military schools”, tells us Marcomede Rangel. In 1871, it was removed from military administration and a French scientist Emmanuel Liais, a friend of Emperor Pedro II, was appointed director for the first time. He focused on directing the observatory’s work toward scientific research and services in the fields of meteorology, astronomy, geophysics, time measurements, and determination of the hour.

National Observatory

Eclipse of the Sun photographed in Sobral (1919)National Observatory

Belgian military engineer and astronomer Luis Cruls followed Liais after the latter’s second term as head of the NO, from 1874 to 1881. While the NO was headed by Cruls, he continued to produce the Observatory Yearbook (Anuário do Observatório), published since 1853, under Antonio Manuel de Mello. This was one of the earliest Brazilian technical publications and it is published to this day. At this time, some important expeditions also took place, one of which took place in 1882, when a mission went to Punta Arenas, in the subantartic region, to observe the passage of Venus across the solar disk, in order to determine the distance between the Earth and the Sun, as part of a global scientific project. Another expedition, from 1892 to 1893, visited Central Brazil. This was headed by Cruls himself. The purpose was to choose the quadrilateral – the Federal District – where the country’s new capital would be built.

“At a time when Brazil was experiencing its first years of independence from Portugal, the observatory measured the time and helped to define Brazil’s borders; in other words, it constructed the notions of time and space in this country, which are essential when thinking about a nation”, states Henrique Lins de Barros, a biophysicists from the Brazilian Center of Physical Research and a former director of MAST, the Astronomy and Related Sciences Museum, an institution established in 1985 and derived from the NO itself. “The arrival of Liais in Brazil, and the work of Cruls and of many others transformed the observatory into an institution that not only provided fundamental services, but also initiated scientific activities of an academic nature.”

In 1908 Henrique Morize took over the position of observatory head after Cruls, and fought for a new NO building, which was to be better equipped and staffed by qualified professionals. In 1922, the observatory left the Castelo hill (the current Castelo esplanade) and moved to the São Januário hill, in the district of São Cristóvão. Morize coordinated the work of the English expedition that, in 1919, documented the full eclipse of the Sun in Sobral (state of Ceará). Also seen from Prince’s Island, the phenomenon became famous because it corroborated Albert Einstein’s General Relativity Theory, by helping to show that light from the stars was deflected by the Sun’s gravity. It was Morize who suggested Sobral for the observation of the phenomenon within its range of visibility. “The NO team was not responsible for the measurements, which were taken by the English, but it was there and built the infrastructure”, says Barros. Six years later, Einstein himself visited the NO and was received by the Brazilian astronomers who had been at Sobral.

Astronomic research has always drawn more attention from people, but geophysical surveys throughout Brazil resulted in the implementation, as from 1955, of reference networks of the field of gravity and, as from 1915, of geomagnetism, thanks to the establishment of a Magnetic Observatory at Vassouras (state of Rio de Janeiro).

In 1981, the Brazilian Astrophysical Laboratory was opened in Brasópolis (state of Minas Gerais). This was spun off the NO four years later, giving rise to the National Astrophysics Laboratory, as it is now called. “Brazilian astronomy was able to have its large telescope as from this time, thanks to director Luiz Muniz Barreto”, says Marcomede Rangel. The 1.6 m National Astrophysics Laboratory telescope has been one of the devices largely responsible for the progress of astronomy in Brazil over the last ten years.

Established in Brazil for almost 30 years and with a great deal of experience acquired in research centers in the USA and in Israel, American physicist Reuven Opher, from the Institute of Astronomy, Geophysics and Atmospheric Sciences at the University of São Paulo confirms this change. “Previously, Brazilians published a lot less in good periodicals in this area”, he said. “Now, there are good groups from the NO that publish a lot and are of an international level, such as the one doing work on dark energy”. Sueli Viegas, a researcher at the said Institute, mentioned another NO group that enjoys international renown; its work focuses on the solar system, dynamic astronomy and planetary systems, under the coordination of Daniela Lazzaro.

National Observatory

The observatory’s campus in 1930National Observatory

As mentioned, the NO does not produce basic science only. In this century, it has focused in particular on research capable of yielding innovative technologies in Brazil. Together with CBPF (the Brazilian Center for Physics Research) and LNCC (the National Scientific Computing Laboratory) it formed a Technological Innovation Center. In 2004, the Time and Frequency Metrology area – in charge of Brazil’s official time – certified the Time Stamp, a product that adds legal value to electronic documents and also functions as a registry of electronic transactions, avoiding falsification of the contents of the document.

In the future, astronomers will look less and less at the sky. “Nowadays, almost all the work is done with computers”, says Reuven Opher. “Astronomers’ function is to interpret the information received”. The romantic image of the solitary astronomer gazing at the stars through a telescope in the wee hours of the morning has definitely fallen by the wayside.