The Štefánik Observatory can be found in the Lesser Town on Petřín Hill.
It was established by the Czech Astronomical Society and the entire observatory was completed in 1930. Due to the lighting of the centre a plot at the Hunger Wall was chosen. The observatory was named after an important Slovak astronomer, who was also a general in the French army, a pilot, diplomat and Minister of War of Czechoslovakia Milan Rastislav Štefánik.
The great event of the time was the placement of the Zeiss double astrograph in the new main dome. It was a very valuable telescope with a primary mirror of 400 mm in diameter, which was purchased for an advantageous price from the estate of the Viennese astronomer Rudolf König. For that time it was technically difficult to transport the telescope from Vienna and install it in the dome.
Finally it was mounted on a 15-metre pillar, walled in the foundations at a depth of 7.5 m. President T.G. Masaryk also contributed to the event.
The observatory underwent a reconstruction and expansion in 1971 – 76. It has also significantly improved its equipment, so today the observatory has a telescope lens with a larger diameter than the original Zeiss telescope. The Zeiss telescope, however, remains its main attraction.
The public may visit two out of the four observatories.
In the daytime and in clear weather it is possible to observe the sun with sunspots, prominences or even the planet Venus.
The evening is ideal for observing the surface of the Moon and some other planets. One can also see multiple stars, star clusters, galaxies and nebulae. All observations are accompanied by expert commentary.
Interesting fact:
The modern mirror telescope of the Maksutov-Cassegrain type, which is located in the western dome, has a lens that lets you watch up to 2,600 times smaller objects than those which can be viewed by the naked eye.
