The CTA Observatory Inaugurates Four Large Telescopes in the Canary Islands

The Cherenkov Telescope Array Observatory (CTAO) is a large network of telescopes dedicated to observing high-energy phenomena, specifically gamma rays.

It is currently under construction at two sites, one of which is in the Canary Islands, where four large, 45-meter-tall telescopes have just been inaugurated. Ultimately, the array will also include medium-sized (27-meter-tall) and smaller (9-meter-tall) telescopes.

The goal will be to detect the characteristic light (known as Cherenkov light) emitted when gamma rays from space enter Earth’s atmosphere. This will provide insights into the origin of these highly energetic rays, which come from active galaxies with massive black holes, star-forming regions, and supernovae, among other sources.

CTAO is a major international collaboration involving, among others, about ten laboratories in France, including the Leprince-Ringuet Laboratory (LLR*) on École Polytechnique's campus.

“The inauguration of these telescopes is just the first step,” emphasizes Mathieu de Naurois, research director at LLR, professor in the physics department at École Polytechnique, and vice president of the CTAO board of directors. “The observatory comprises two sites, which will eventually be equipped with numerous telescopes. The northern site, on the island of La Palma, will house, in addition to the four large telescopes, nine medium-sized telescopes. The southern site, in Chile, will consist of a total of 53 telescopes of all three sizes, covering a total area of 3 km². The École Polytechnique’s Leprince Ringuet Laboratory is participating in the construction of nine NectarCam-type cameras, which will be installed on the medium-sized telescopes. Their installation is set to begin as early as 2027.”

*LLR: a joint research unit CNRS, École Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France