CTAO ERIC Consortium established

On January 7, 2025, by Commission Implementing Decision (EU) 2025/7, the European Commission established the European Research Infrastructure Consortium Cherenkov Telescope System Observatory (CTAO ERIC). Thus, the nearly seven-year effort of the participating countries towards the establishment of a European consortium as the final legal entity, whose goal is the construction and operation of a system of 120 Cherenkov telescopes for observing the universe in the field of gamma rays of the highest energies, was completed. The observatory itself will consist of two parts – the northern part on the island of La Palma (Canary Islands, Spain) with a total of 21 telescopes and the southern part in the Paranal region (Chile) with a total of 99 telescopes. Intensive construction of the observatory is already taking place in both parts – in the southern part, the road and network infrastructure is being built, in the northern part, the first telescopes are already being constructed. The research infrastructure also includes a data center located in Germany and a headquarters located in Bologna, Italy. In addition to the host Italy, the founding members of the consortium are the Czech Republic, France, Germany, Poland, Austria, Slovenia, Spain and ESO (European Southern Observatory). Switzerland will become the founding observer of the consortium, Japan will be a strategic partner, and other cooperating countries will include Australia and Brazil. Cooperation will also take place with individual research organizations from the USA. The CTAO ERIC consortium will thus have a global reach.

CTAO – southern site (visualization)

CTAO European research infrastructure

Activities aimed at building the CTAO observatory have so far been carried out under the CTAO gGmbH organization, within which the telescopes themselves have been developed in 3 sizes – large (LST), medium (MST) and small (SST) – specialized in different parts of the high-energy spectrum. The first prototypes of these telescopes were constructed and tested, their optimal placement in selected locations was modelled, and the construction of infrastructure and utility networks began. The European Research Infrastructure CTA was included in the Roadmap of the European Strategic Forum for Research Infrastructures in 2008, and since 2018 it has been led as a so-called Landmark. The Czech Republic is involved through the large research infrastructure CTA-CZ, included in the Roadmap of large research infrastructures of the Czech Republic.

Cherenkov telescopes (SST, MST, LST)

Cherenkov Telescope Array Observatory – participation of the Czech Republic

The CTA-CZ large research infrastructure has been on the Roadmap of Large Research Infrastructures of the Czech Republic since 2016. The Czech main contribution to the observatory is participation in the preparation and testing of optical surfaces for the MST and SST telescopes (the Czech Republic participates in the consortium, which developed the SST-1M telescope; unfortunately, it didn’t become the selected type of SST for the southern site of the observatory despite its undeniable advantages). The Czech Republic will also supply the FRAM telescopes for monitoring aerosols in the air. These telescopes have already been used to select sites for the observatory’s location, monitoring clouds in selected region. A pair of the SST-1M telescopes was installed on the premises of the Ondřejov Observatory, where they are tested in real conditions, including astronomical observations. At the same time, visitors of the observatory can see them, as they are in an open space outside the building, as is typical for this type of telescopes. Although these are small telescopes (small-size telescope), with a mirror diameter of 4 meters they are the largest telescopes in the Czech Republic.

SST-1M telescope at the observatory in Ondřejov

Involvement of the Czech Republic in the CTAO ERIC consortium

The Czech Republic is engaged in the CTAO ERIC consortium through the Ministry of Education, Youth and Sports (MEYS) and the CTA-CZ large research infrastructure project of the Institute of Physics of the Czech Academy of Sciences. MEYS is financing the CTA-CZ large research infrastructure project with a special grant amounting to CZK 18.2 million in 2025. With the establishment of CTAO ERIC, the Czech Republic has already become a member country of 19 ERIC consortia, which testifies to the significant internationalization of the Czech research environment and the status of national large research infrastructures on a European scale.