Refined laboratory simulations of dark-speckle coronagraphy

¹ DESPA, Observatoire de Paris-Meudon, 5 Pl. J. Janssen, F-92195 Meudon, France e-mail: boccalet@despa.obspm.fr
² ESO Santiago, Chile e-mail: cmoutou@eso.org
³ Observatoire de la Côte d'Azur, Département Fresnel, ISA-GI2T, F-06460 Saint Vallier de Thiey, France e-mail: lyuabe@obs-azur.fr

Send offprint request to: A. Boccaletti

Received: 2 June 1999
Accepted: 29 September 1999

Abstract

Dark-speckle coronagraphy with large telescopes is expected to image extrasolar planets. We present new results about the dark-speckle coronagraphic camera, obtained in the laboratory with a simulated atmosphere and an adaptive optics bench. In good seeing conditions, and with an accurate subtraction of a reference frame, we show that our instrument allows high-resolution, high-contrast imaging, more effectively than classical long exposure, for magnitude differences larger than 5 at visible wavelength. With the present capability of the adaptive optics system used, on a 1.5 m telescope pupil, we should expect to detect stellar companions 10⁴ fainter than the primary star. Instrument concepts and processing techniques are discussed.