Extreme coronagraphy with an adaptive hologram
Simulations of exo-planet imagingD. Ricci1, H. Le Coroller2, and A. Labeyrie3
1 Département d'Astrophysique, Géophysique et Océanographie, Bât. B5C, Sart Tilman, Université de Liège, 4000 Liege 1, Belgium
2 Observatoire de Haute Provence, 04870 Saint Michel l'Observatoire, France
3 Collège de France, 11, place Marcelin Berthelot, 75231 Paris Cedex 05, France
Received 16 December 2008 / Accepted 15 May 2009
Aims. We present a solution to improve the performance of coronagraphs for the detection of exo-planets.
Methods. We simulate numerically several kinds of coronagraphic systems, with the aim of evaluating the gain obtained with an adaptive hologram.
Results. The detection limit in flux ratio between a star and a planet observed with an apodized Lyot coronagraph characterized by wavefront bumpiness imperfections of /20 (resp. /100) turns out to be increased by a factor of 103.4 (resp. 105.1) when equipped with a hologram.
Conclusions. This technique could provide direct imaging of an exo-Earth at a distance of 11 parsec with a 6.5 m space telescope such as the JWST with the optical quality of the HST.
Key words: instrumentation: detectors -- instrumentation: miscellaneous -- stars: planetary systems -- instrumentation: interferometers
© ESO 2009