The biggest Planetarium with an astronomical observatory in Bulgaria is located in the mountain town of Smolyan. It began operations in 1975 and is one of the most visited tourist attractions in the town.
The Planetarium carries out research, educational and promotional activities.
Research includes daily monitoring of solar activity and sunspots, taking photographs and making records of all lunar and solar eclipses and other curious astronomical phenomena.
The educational activities have to do with the work with students and pre-school children. A Youth Astronomy Club is set up and every year its members go to observational camp-schools.
In order to promote knowledge about astronomy, performances-tales for the youngest children and various overviews and thematic educational sessions for the wide audience are offered in the Stellar Hall of the Planetarium. Performances are also available in Russian, French, German, English, Greek, and Turkish. Special music and poetic performances are added to the variety of stellar shows.
The round stellar hall with a domed ceiling lies in the “Heart” of the Planetarium. The hall is 12.5 m in diameter and has 150 seats. The main projector – a space flight planetarium (RFP), is set in its centre. It creates an artificial starlit sky – an exact copy of the real sky. The apparatus allows for the exact reproduction of the movements of the celestial sphere, the Sun, the Moon, the planets, the different astronomical objects and phenomena.
The dome of the observatory at the Planetarium is 3 m high. A reflecting telescope is installed under it. There are also several other telescopes in the planetarium which, on clear-sky days, allow people to observe the Sun and the active areas of the solar photosphere. Every Wednesday evening they give them the opportunity to watch the Moon, different planets, double stars, star clusters, nebulae, galaxies, etc.
A sundial, a vertical gnomon and an observation platform where small portable telescopes are installed are built on the astroplatform. The gnomon is a simple ancient astronomical device – a vertical pole set on a horizontal platform whose shadow can be used to determine the position (the height and the direction) of the Sun in the sky.
A permanent exhibition of original paintings is displayed in the central lobby. Temporary thematic exhibitions are also organized.