Cherenkov Telescope Array Observatory

The Cherenkov Telescope Array Observatory (CTAO) is a multinational project to build a new generation of ground-based gamma-ray instruments in the energy range extending from some tens of GeV to about 300 TeV. It is proposed as an open observatory and will consist of two arrays of imaging atmospheric Cherenkov telescopes, a first array at the Northern Hemisphere, on the Spanish island of La Palma, with emphasis on the study of extragalactic objects at the lowest possible energies, and a second array at the Southern Hemisphere, in the Atacama Desert in Chile, which is to cover the full energy range and concentrate on galactic sources. The physics program of the CTAO goes beyond high-energy astrophysics into cosmology and fundamental physics.

Building on the technology of current-generation ground-based gamma-ray detectors (MAGIC, HESS, and VERITAS), the CTAO will be ten times more sensitive and have unprecedented accuracy in its detection of high-energy gamma rays. Current gamma-ray telescope arrays host up to five individual telescopes, but the CTAO is designed to detect gamma rays over a larger area and a wider range of views, with more than 60 telescopes located in the northern and southern hemispheres.

In January 2025, the CTAO was established as a European Research Infrastructure Consortium (ERIC) by the European Commission.

The project is part of the Aspera European Astroparticle network and of Astronet.