Open Days at the Observatory in Ondřejov 2026
Astronomický ústav AV ČR, Ondřejov
free entry
The Astronomical Institute of the Czech Academy of Sciences in Ondřejov opens its doors on Friday 15 and Saturday 16 May 2026, from 9 to 18 hours each day. Admission and all accompanying programmes are free. Schools are invited on Friday.
The programme includes tours of the Perkin two-metre telescope – the largest telescope in the Czech Republic (main mirror diameter 2 m, weight 83 tonnes) – and tours of the Solar Department with solar patrol and a 10-metre solar radio telescope. Visitors can also see the Mayer telescope with a 65 cm diameter in the Interplanetary Matter Department and the D50 telescope of the High-Energy Astrophysics Group in the Stellar Department. Guided tours of the exhibition on the history of meteor physics research (bolides and meteorite falls) depart with a guide from the V. Šafařík Museum every even hour (10, 12, 14 and 16). In the Stellar Department in the Perkin telescope dome, a space room is prepared with projections on the themes "A Night in the Life of an Astronomer" and "Stellar Imprints and the Origin of Elements".
On Saturday 16 May from 18:30, a concert by Václav Havelka (guitar and vocals, central figure of the band Please The Trees) takes place in the historic part of the observatory; admission is by donation. On Friday and Saturday evenings, weather permitting, sky observation with a telescope from the Western dome of the historic observatory is possible. Refreshments are provided on Saturday from 10 to 17 hours by "Ondřejovský koláč" in the Solar Department building and Café from SKC Ondřejov in the new seminar building. On Saturday from 9 to 18 hours, next to the car park, there is an exhibition of small livestock (pigeons, rabbits, poultry) with a rich raffle. The observatory is located 30 km south-east of Prague, accessible by car (D1, exit 21, direction Benešov) or by bus line 383 from Háje metro station (line C).