This image illustrates the CTAO’s southern hemisphere site or CTAO-South. The array is located less than 10 km southeast of the European Southern Observatory’s (ESO’s) existing Paranal Observatory in the Atacama Desert in Chile, which is considered one of the driest and most isolated regions on Earth – a paradise for stargazers. Credit: CTAO. CC BY-NC-ND.

The Cherenkov Telescope Array Observatory (CTAO) is set to become the world’s most powerful gamma-ray observatory.

The European Commission has established the Cherenkov Telescope Array Observatory (CTAO) as a European Research Infrastructure Consortium (ERIC), furthering its mission to become the world’s largest and most powerful observatory for gamma-ray astronomy.

The creation of the CTAO ERIC will enable the observatory’s construction to advance rapidly and provide a framework for distributing its data worldwide, significantly accelerating its progress toward scientific discovery.

Dr Aldo Covello, chair of the Board of Governmental Representatives (BGR), said: “The ERIC will streamline the construction and operation of the observatory in a way that will undoubtedly help the CTAO attract new talent and investment as it continues to grow.

“The ERIC status provides the CTAO with the legal stability and administrative advantages it needs to be sustainable in its worldwide operations and impact.”

The CTAO ERIC was established with the international support of 11 countries and one intergovernmental organisation that contribute to the technological development, construction and operation of the observatory. The BGR represents this group and has been responsible for the preparation of the ERIC.

CTAO managing director Dr Stuart McMuldroch, said: “We are grateful to our founding members for their support and to the European Commission for reaffirming their confidence in the CTAO as a world-class research infrastructure.

“This milestone represents the culmination of years of dedicated planning by the diverse teams contributing to the success of the observatory.

“With the CTAO ERIC, we now have a powerful instrument to consolidate our efforts and drive the project forward.”

This is an artistic rendering of the CTAO’s northern hemisphere site or CTAO-North. The site already hosts a prototype of the Large-Sized Telescope, the LST-1 (top left), but the plan is for the site to host four LSTs and nine Medium-Sized Telescopes (MSTs) to cover CTAO’s low and medium energy range. The array is located on the existing site of the Instituto de Astrofísica de Canarias’ (IAC’s) Observatorio del Roque de los Muchachos on the island of La Palma in the Canary Islands (Spain). At 2,200 metres altitude and nestled on a plateau below the rim of an extinct volcanic crater, the site currently hosts a variety of telescopes operating at different wavelengths, including the Telescopio Nazionale Galileo (TNG) and Gran Telescopio de Canarias (GTC), visible in the upper part of the image, as well as CTAO predecessor the Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) telescopes (not pictured). Credit: CTAO. CC BY-NC-ND.

Prototypes

The ERIC not only provides the central organisation with a formal framework to accept and operate the current telescope prototypes, but it also allows for the immediate start of construction for the full array of more than 60 telescopes across both telescope sites in Spain and Chile.

On the CTAO-North site, where the Large-Sized Telescope prototype (LST-1) is under commissioning, three additional LSTs and one Medium-Sized Telescope (MST) are expected to be built in the next one to two years.

Meanwhile, on the CTAO-South site, the first five Small-Sized Telescopes (SSTs) and two MSTs are expected to be delivered by early 2026.

Thus, with the aid of the ERIC, the observatory is expected to be able to operate intermediate array configurations as early as 2026.

These sub-sets of the final arrays will already be more sensitive than any existing instrument, bringing the observatory’s early science within reach.

The impact of the ERIC will extend beyond hardware, influencing several other key areas.

In the coming months, the observatory will prepare to integrate and operate advanced software designed to control the telescopes and their supporting devices on-site, as well as to manage data processing.

Additionally, the ongoing recruitment campaign will continue across all CTAO facilities, including the CTAO headquarters in Italy and the CTAO Science Data Management Centre in Germany, ensuring robust support for these developments.

C0-managing director Professor Federico Ferrini said: “The ERIC status strengthens the presence of the CTAO in Europe and its role as a key player in the European Research Area, but the support we have received and the scope of the CTAO ERIC’s influence goes far beyond European borders.

“To build and operate the world’s largest gamma-ray observatory that serves the ambitious needs of the global scientific community, we are counting on an increasing number of partners from around the world.”