The CTAO will double its staff as major infrastructure development begins in 2024

25 September 2023

Progress in the Cherenkov Telescope Array Observatory (CTAO) –– the world’s most powerful ground-based gamma-ray observatory –– will be bolstered by a recent funding pledge from its governing bodies. On 6 September 2023, the CTAO’s Board of Governmental Representatives and the CTAO gGmbH Council, of which ESO is a member, met to agree on the next steps to advance the CTAO to its construction phase. As part of their unanimous commitment to the progress of the project, all members agreed on a foreseen endorsement of up to approximately 30 million euro for 2024. This significant increase in the CTAO’s funding will allow it to build new infrastructure and double the workforce.

The CTAO will consist of two arrays of telescopes: CTAO-North in La Palma, Spain, and CTAO-South at ESO’s Paranal Observatory in Chile. After extensive design and pre-construction activities, such as testing a prototype telescope in the northern site, the new funding pledge will allow the CTAO to proceed forward on various fronts. In particular, in 2024 the CTAO plans to open at least 30 new positions, and start major infrastructure development in its southern site such as building roads, power systems, and foundations. “We welcome the steadfast commitment of all members to the progress of the CTAO, and we look forward to hosting the southern array at our Paranal site,” said Xavier Barcons, ESO Director General.

The CTAO currently operates as a gGmbH –– a non-profit limited-liability entity under German law –– and is now in the process of becoming a European Research Infrastructure Consortium (ERIC), which will function under European law. The first step of this process has been completed, and discussions with the European Commission about the second step are still ongoing. This new agreement between the  governing bodies of the CTAO will allow the project to keep moving forward in the meantime.

In its planned configuration, the CTAO will comprise 64 telescopes of different sizes, 13 in the northern site and 51 in the southern one. These telescopes will detect the faint and ephemeral radiation produced when high-energy particles from deep space hit our atmosphere, thus probing the most powerful and extreme events in the Universe with unprecedented sensitivity. CTAO’s high-energy capabilities constitute a perfect match to ESO’s current roster of telescopes, which observe all the way from visible/infrared light to submillimetre wavelengths, a synergy that will allow astronomers to study the Universe in brand new ways.



Juan Carlos Muñoz Mateos
ESO Media Officer
Garching bei München, Germany
Tel: +49 89 3200 6176

About the Announcement



An artist’s rendition of the CTAO-South telescope array at ESO’s Paranal Observatory in the Chilean Atacama Desert. Tens of gamma-ray telescopes — shiny, parabolic dishes of different sizes — sit on a brown plain in the foreground. Faint mountaintops can be seen in the distance. The Milky Way stretches across the night sky in the top third of the image, with the glow of stars intermingling with the shrouds of cosmic dust.
Artist’s rendering of the CTAO southern site
An artist’s impression of the CTAO-North telescope array under the sunny blue sky of La Palma, Spain. Several reflective parabolic dishes of varying sizes are dotted along the green hillside, which slopes down from left to right. The dishes themselves are made up of numerous hexagonal segments. In the background, further up the slope, a couple of white telescope domes that are not a part of CTAO can be seen peeking over the brow of the hill.
Artist’s rendering of the CTAO northern site