From 19 to 21 November 2025, the CTAO ERIC Council convened at the CTAO Science Data Management Centre (SDMC) in Zeuthen, Berlin, for its fifth meeting. During the session, the Council unanimously approved a revision of the CTAO ERIC Statutes to formally include Switzerland and Croatia as full members, granting them corresponding voting rights.
Switzerland and Croatia were initially endorsed as members by the CTAO ERIC Council in June 2025. Following internal approval, the European Commission was formally notified, allowing the Statutes to be updated to reflect their membership. The modification approved at November’s meeting not only confirms their status as Founding Members—joining within 18 months of the ERIC’s establishment—but also grants both countries full membership rights.
“The addition of Switzerland and Croatia to our growing membership strengthens the CTAO community and underscores our shared commitment to advancing gamma-ray astronomy and astroparticle physics across and beyond Europe,” says Francisco Colomer, Chair of the CTAO ERIC Council.
Both countries have long supported the CTAO, particularly through their contributions to in-kind collaborations, which have advanced the development of telescope hardware and the Observatory’s computing infrastructure. As official Council members, Switzerland and Croatia will continue to contribute to the development of the Observatory, enabling their respective scientists and institutions to actively participate in the CTAO’s scientific programme. This will reinforce their participation in gamma-ray, astroparticle, and multi-messenger astronomy, while fostering national expertise in data science and enabling broader participation of their scientific communities.
The CTAO ERIC members now include Austria, Croatia, the Czech Republic, the European Southern Observatory (ESO), France, Germany, Italy, Poland, Slovenia, Spain, and Switzerland. Further countries — Australia, Brazil, Japan, South Africa, and the United States — are engaged in the process of joining the CTAO ERIC as Strategic Partners or Third Parties.
