The Instituto de Astrofísica de Canarias (IAC), hosting partner of the CTAO, celebrated its 40th anniversary on 24 July 2025. The occasion marks four decades since the official inauguration of its headquarters and its two observatories: the Teide Observatory in Tenerife and the Roque de los Muchachos Observatory in La Palma, Canary Islands— the latter being the site of the CTAO-North array.
This milestone is commemorated under the theme ‘Soñando Estrellas’ (‘Dreaming of Stars’), the title of a book in which Francisco Sánchez, the IAC’s founding director, recounts the history of the institute.
The celebration took place at the Roque de los Muchachos Observatory and included speeches by IAC Director and delegate for Spain in the CTAO ERIC Council, Valentín Martínez Pillet; Minister for Territorial Policy and Democratic Memory, Ángel Víctor Torres; Minister for Science, Innovation and Universities, Diana Morant; and President of the Canary Islands, Fernando Clavijo. Among other distinguished attendees were the President of the Cabildo of La Palma, Sergio Rodríguez; the President of the Cabildo of Tenerife, Rosa Dávila; the Rector of the University of La Laguna (ULL), Francisco García; and the President of the Spanish National Research Council (CSIC), Eloísa del Pino Matute, along with various international, national, regional, and local authorities.
The CTAO had a strong presence at the anniversary, underlining its close partnership with the IAC and its role in the site’s continued scientific growth and excellence. The IAC’s Roque de los Muchachos Observatory is home to CTAO-North, one of the CTAO’s two telescope arrays — the other, CTAO-South, is located near ESO’s Paranal Observatory in Chile. CTAO-North will host two of the three types of telescope that the CTAO will deploy: the Large-Sized Telescopes (LSTs) and the Medium-Sized Telescopes (MSTs). At present, the site includes the LST prototype, LST-1, which is undergoing commissioning, along with three additional LSTs under construction by the CTAO LST Collaboration. It will also include an operations building and calibration and atmospheric characterisation devices.
Representing the CTAO ERIC at the anniversary were Francisco Colomer, Chair of the CTAO ERIC Council and Programme Director at the Spanish Deputy Directorate General for International Consortia, Organisations and Research Infrastructures; Volker Heinz, Construction Programme Manager; and Patricia Márquez, Construction Lead Engineer.
“Being present at the IAC’s Roque de los Muchachos Observatory (ORM) to celebrate these first 40 years of great success in science, while the site is currently attracting new unique infrastructures such as the CTAO, demonstrates the great vision of the founders, the dedicated work of the scientists, and the constant support of many administrations. I personally feel pride and honour that this is happening in Spain,” said Francisco Colomer.
Also present were representatives of different CTAO teams, including Ramón García, Principal Investigator of the CTAO group at the IAC; Masahiro Teshima, Principal Investigator of the LST Collaboration; Daniel Mazin, LST Project Manager; and Alice Donini, LST Deputy Project Manager.
The CTAO delegation guided attendees on a detailed tour of the CTAO-North site, showcasing the LST-1 prototype and giving authorities and guests firsthand insight into the array’s significant progress.
In his speech, Valentín Martínez spoke of the evolution of Cherenkov telescopes. “These telescopes were unimaginable 40 years ago. Today they are a reality in La Palma. They are also being built in Chile, but — for now — we have the world’s largest concentration of this type of telescope,” he emphasised.
La Palma holds a unique place in the history of ground-based gamma-ray astronomy, having hosted three generations of Cherenkov telescopes. These include decommissioned HEGRA array and the still-operational MAGIC Telescopes, both predecessors of the CTAO, which will be the first to operate as an open, proposal-driven observatory.
Congratulations to everyone at the IAC on four decades of pioneering work and excellence—we look forward to many more years of collaboration and discovery!
