Astron. Astrophys. Suppl. Ser. 145, 445-449

Gain estimate for exoplanet detection with adaptive optics

V.F. Canales - M.P. Cagigal

Send offprint request: V.F. Canales,
e-mail: mpc@opt.unican.es

Dpto. de Fisica Aplicada, Universidad de Cantabria, Avda. Castros S/N, 39005 Santander, Spain

Received June 9; accepted June 9, 2000

Abstract:

Atmospheric turbulence imposes the resolution limit attainable by large ground-based telescopes. Adaptive optics systems can compensate turbulence-induced distortions. One of the most difficult task for telescopes assisted by adaptive optics systems is the detection of extrasolar planets since a compensation level higher than in other applications is needed. In this context, the gain of the system (ratio between the peak and the halo intensity) gives a good description of the system performance. A way to theoretically estimate the system gain and a technique to estimate it from the measurement of the experimental Strehl ratio are developed using a single model of the PSF of compensated wavefronts. From it, the integration time required to detect a Jupiter-like planet is derived from the number of system actuators and the atmospheric conditions.

Key words: atmospheric effects -- techniques: image processing -- telescopes