image of telescopes

Linnaeus Physics Colloquium: Optical astronomy & intensity interferometry

Welcome to Linnaeus Physics Colloquium, a series of seminars delivered by renowned researchers in physics.

Photo: Akihiro Ikeshita, Mero-TSK, International

Title: Cherenkov Telescope Array: Optical astronomy & intensity interferometry
Lecturer: Dainis Dravins, Lund Observatory

Coffee and buns will be served. Please register using this form if you want to participate in the seminar.


CTA, Cherenkov Telescope Array, is a project for studying the high-energy Universe in gamma-rays. Under construction on La Palma and in Chile are arrays of its numerous telescopes. These telescopes are optical, inferring gamma rays from flashes of visible Cherenkov light produced in the Earth’s atmosphere. The many telescopes with an unprecedented light-collecting area of some 5,000 m^2, distributed over several square km, will enable projects in also optical astronomy, such that can tolerate their imperfect mirror surfaces.

Such include stellar occultations by distant asteroids in our solar system, and the connection of many telescopes for intensity interferometry. Their electronic connection circumvents effects of atmospheric turbulence, enabling an optical equivalent of radio interferometers. CTA as an interferometer will be able to resolve stellar surfaces, image rotationally flattened stars with circumstellar disks and winds, monitor some nova eruption, or possibly even visualize an exoplanet during its transit across some nearby star.

An illustration of intensity interferometry
An illustration of intensity interferometry.