The Ondrejov Observatory

The Ondrejov Observatory, foto: Roman Casado

In this week's Spotlight, we visit the Ondrejov Observatory 35km south-east of Prague, where some 50 scientists are busy solving the mysteries of the universe. The observatory has been part of the Astronomical Institute of the Academy of Sciences of the Czech Republic since 1953 and houses the biggest telescope in Central Europe. It's open to the public every weekend in the summer from 9 a.m.

Dr. Petr Heinzel,  foto: Roman Casado
Dr. Petr Heinzel is Director of the Astronomical Institute:

"The observatory was founded at the beginning of the last century. It was in fact a private observatory that was created by Dr. Josef Jan Fric from Prague. Then, in 1928, he donated this observatory to Prague University and after WWIII, when the Czechoslovak Academy of Sciences was founded in 1953, this observatory became part of the Astronomical Institute of the academy. We are working in several fields. The main ones are: stellar astrophysics, solar physics, galactic research, the study of interplanetary matter, and the study of dynamics and physics of bodies in the solar system. To be more specific, we are studying the sun, in particular its atmosphere, from which we obtain all the information about the sun's structure and physics, especially solar activity, which is manifested by big flares, eruptions of the sun, which have an important impact on Earth, for example. In the solar system, we study various bodies, namely the motion of planets, especially the rotation of Earth. We also study the dynamics of asteroids. Some of them are approaching Earth very closely and could be dangerous sometimes - we can even expect some interaction of asteroids with Earth, fortunately it hasn't happened so far but it could in the future."

There are about fifty scientists working here. What are some of the main projects they are working on in international cooperation?

The biggest telescope in Central Europe,  foto: Roman Casado
"Each scientist has his own international collaboration with many colleagues. But we also participate in some bigger international projects. Currently, we are collaborating with a German consortium, which is building the largest solar telescope. This telescope will be placed on Tenerife, which belongs to the Canary Islands. But there are also other observatories. Several western countries gradually created the European Southern Observatory, ESO, which has its administrative building near Munich but the observatory itself is in the mountains in Chile and there are large telescopes to observe very distant objects in the universe and our country is now in the process of trying to join."

Before we walk over to the observatory and the biggest telescope in Central Europe, could you tell us about your space programme?

"Yes. We have built some space instruments in our institute. For example, we built an instrument for the measurement of x-ray radiation from the sun. This detector was installed on the US satellite and measured solar radiation for three years. We also built a special instrument called the micro-accelerometer, which is a special Czech satellite to measure the gravitation of Earth and other influences on the satellite. We also participate in large international projects, especially in the European Space Agency programme. For example, solar astronomers from our institute use data from a big satellite, which contains twelve large telescopes and is placed between Earth and the sun to observe the sun 24 hours a day."

We are now standing next to a huge telescope, which is two meters in diameter. Next to me is Mr Petr Hadrava, who is going to tell us more about it:

The Ondrejov Observatory,  foto: Roman Casado
"In 1967, when this telescope was put into operation, it was among the ten largest telescopes in the world. However, today it is already concerned as an average or even small telescope because there are now much larger ones, which are usually also placed in places with much better weather conditions - in deserts or on top of high mountains. Nonetheless, this telescope is very useful for Czech stellar astrophysics because it enables us to do spectroscopic research of stars and the stellar systems. All the data collected also enables us to improve our theories about the structure and evolution of stars."

How often is it put into operation?

"This telescope is used on every clear night, which in our weather conditions comes to about 100-120 nights a year."

We are now inside an observatory, which is actually a museum. Dr. Heinzel, what can visitors find here?

"This is the old observatory built by Dr. Fric and this is the old telescope dome, which is no longer being used for observations, so we created a small astronomical museum. Here you can see the old telescope, which is over one hundred years old, you can also find other instruments which were partly built by the small company of Dr. Fric in Prague and other companies. In the other dome, we have some photographs on the history of the observatory."

Why is the frog an important symbol here?

"The nineteenth century Czech poet Jan Neruda wrote poems called the 'Cosmic Songs', where frogs discuss about possible life in the universe. The smaller ones ask the bigger frogs whether there are also frogs in the universe and Dr. Fric and his friends loved the Cosmic Songs poems and that is why you see so many frogs featured here. Actually, the first wooden observatory which was built here to test the site, before these buildings were finished, was called the Observatory at the Green Frog."