SATLASGamma ray · Ground
CTAO
Cherenkov Telescope Array Observatory
Under constructionUnder construction; first telescope (lst-1) expected October 2018.
LST-1 has observed since 2018. All four Large-Sized Telescopes on La Palma were structurally complete in June 2026 and are in final commissioning; the rest of the northern (La Palma) and southern (Paranal) arrays are being built.
Imaging atmospheric Cherenkov telescopesCherenkov lightLight emitted when a charged particle moves faster than light's phase velocity in a medium. Ground gamma-ray telescopes image the nanosecond flash from the particle shower a TeV photon makes in the atmosphere; neutrino detectors see it from secondary particles in ice or water. in three sizes (23 m for the lowest energies, 12 m, and 4 m for the highest) on two sites, covering 20 GeVelectronvoltThe energy an electron gains across 1 volt, 1.602 × 10⁻¹⁹ J. High-energy astronomy labels photons by energy: optical light is about 1.7–3.1 eV, X-rays 0.1–100 keV, gamma rays from about 100 keV to beyond 100 TeV. A 1 keV photon has wavelength 1.24 nm.–300 TeV with about an order of magnitudemagnitudeA logarithmic flux scale, m = −2.5 log₁₀(F/F₀): five magnitudes is a factor of 100, and larger is fainter. The naked eye reaches about 6; single Rubin exposures reach about 24 in r. better sensitivity than current arrays and arcminute-scale resolution at TeV energies. Targets particle acceleration in supernova remnantssupernova remnantThe expanding debris and shocked interstellar gas left by a supernova, bright in X-rays for thousands of years. X-ray spectra give its temperature and the elements the explosion made. and AGN jets, gamma-ray burstsgamma-ray burstA flash of gamma rays lasting milliseconds to minutes, followed by a fading afterglow at longer wavelengths. Long bursts come from collapsing massive stars; short ones from neutron-star mergers., and dark-matter annihilation signals.
- Operator
- CTAO ERIC
- Site
- La Palma, Spain and Paranal, Chile
- Passband
- 20 GeV – 300 TeV
- First telescope (LST-1)
- October 2018
Passband
Sky coverage
Pointed observationspointed observationObserving chosen targets, usually selected by peer review in annual proposal cycles, as opposed to surveying the sky systematically. Gives depth on few objects; the total area observed stays small. from both hemispheres, mostly on moonless nights; the southern array has the best view of the Galactic centre and inner plane.
Archives
Sources
Verified 15 November 2026.