Interferometry spots an exoplanet

Abstract

Exoplanets\nOptical interferometry combines the light from multiple telescopes to reach very high angular resolution but is challenging to apply to high-contrast sources such as an exoplanet orbiting a star. The GRAVITY Collaboration observed the star HR 8799 and one of its planets, HR 8799 e, using an optical interferometer fed by four 8-meter telescopes. They detected the planet, measured its position more precisely than has been done using previous methods, and extracted a near-infrared spectrum that constrains the composition of its atmosphere. This is the first exoplanet to be detected with interferometry. Although HR 8799 e was already known, the interferometry technique could be used to refine the orbits and spectra of directly imaged exoplanets.\n\nAstron. Astrophys. 623 , L11 (2019).