Unknown Wrocław: window to the universe

This time curiosity led us to the observatory and planetarium of the Astronomy Institute of the University of Wrocław (Uniwersytet Wrocławski) at ul. Kopernika. When passing by the characteristic buildings, many people wonder what they house. We took a peek inside. It used to be the window to the universe for scientists. Now it serves for educating students and houses a planetarium.

The present location of the Wrocław observatory is not the first place in the history of Wrocław science where scientists used to watch the stars. At first, such place was the Mathematics Tower (Wieża Matematyczna), now known mainly as a viewpoint. At first, observations were held occasionally there. It was only due to Professor Longinus Anton Jungnitz, who turned the facility into an observatory in years 1790-1791, that academic astronomy was born in Wrocław. At the time the basic instrument of the observatory was the latitudinal line drawn on the tower's floor, accompanied by a gnomon, one of the oldest and the simplest astronomical instruments. The 17th latitude line is still visible on the tower floor.

Observations from the island

At the end of the 19th century the scientists created a makeshift observatory on Śluz Island (Wyspa Śluz), opposite the University's building. Though arranged in barracks, the observatory was equipped with then impressive astronomical equipment. Later, a part of it ended up in ul. Kopernika.

Plans for moving from the city centre to the outskirts were made as long ago as 1912/1913. But it was only in 1917 that its location was determined on a plot on the outskirts of Szczytnicki Park (Park Szczytnicki). It was a remote place these days, and dark enough for conducting night observations. Today, the conditions are much worse, with dense housing and many sources of light. It took several years before the main telescope made its way under the dome of the main building.

Elite field of studies

We managed to see what was left from those times, and it's quite a lot. Now the park side observatory does not run scientific observations any more. The University of Wrocław keeps its eyes on the universe in Białków, a small village 70 kilometres off Wrocław, where conditions to watch the sky are far better. The observatory at ul. Kopernika runs only occasional observations for enthusiasts and students. Apart from the observatory and teaching buildings we visited also the planetarium, where astronomy is popularised among children and teenagers.

Our guide to the facility is Barbara Cader-Sroka, MS, from the Astronomy Institute. We start with the main building and the library, combined with the teaching room. Books with shelves are set up on the first floor, they are accessed by climbing almost vertical, iron staircase. Among them are, e.g. writings from mid-19th century, signed by Johann Gottfried Galle, the man who discovered Neptune and Saturn's rings, as well as the director of Wrocław observatory. Moreover, it includes old star catalogues and books on the theory of astronomy.

One striking thing about the lecture room is the number of seats it contains. There are so few of them that you can see right away that astronomy is an elite field of study. "There are less than twenty of them, but enough to accommodate everyone, even the first years" says Barbara Cader-Sroka.
We walk up to the first floor, where on a terrace, in a special casings set on tracks sits a small, historical instrument to watch the Sun, made in Berlin. A special set of cogwheels, chains and weighs sets the telescope in motion, equal to the speed of Earth's rotation. It is hard to believe that this is such a precise mechanism, because nowadays the telescope is moved by small electric engines, and all is computer-controlled.

The heart of the observatory

We then walk up to the very top, to the heart of the observatory. Under a meticulously made dome sits a 203-mm refracting telescope of Clark Repsold. It was built in 1881, and has been operating under the dome in Szczytnicki Park since 1925. Until 1945 the refractory telescope was used, among others, for observing positional double stars, comets or star occultations. "It is now at rest, but still remains fully operational. Holding their observations here are enthusiasts of astronomy who take part in popular science lectures organised by the institute" explains Barbara Cader-Sroka.

The dome is opened by a special installation of lines and cogwheels. Though everything was constructed nearly a hundred years ago, operates very efficiently and flawlessly. The gigantic wooden construction can also be fully rotated with electric engines. The room contains maps of the Moon and the sky, as well as furniture - including a historical armchair that allowed the scientists to hold observations comfortably. We also explore a building a bit to the back of the facility, with a roof slid on special tracks. It is where the vertical wheel and Repsold's transit instrument are located, with which data for star catalogues were collected. Research was conducted there even in 1950's. Now such research is conducted with the use of telescopes installed in satellites.

Sky on a big screen

Our tour ends in the planetarium located in the teaching pavilion in the back of the facility. It was born when the scientists from the Astronomy Institute organised a makeshift planetarium in the park for the Lower Silesia Science Fair. The planetarium was so popular that they decided to organise something better for the next edition of the festival. They self-made a curved screen on a special framework, which landed in the institute buildings afterwards, and this is how the mini-planetarium was created. Now it includes a newer and professional construction.

The scientists purchased a quality projector, the light of which is directed to a semi-spherical mirror and is reflected in a properly curved screen. Though the planetarium is intimate, it is nevertheless impressive after the light goes out. It hosts special popular science projections about constellations, stars, galaxies or other heavenly bodies, attended mainly by school students and astronomy enthusiasts.

Janusz Krzeszowski