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Astron. Astrophys. 338, 106-110 (1998)

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Preliminary results of dark-speckle stellar coronography

A. Boccaletti 1, A. Labeyrie 2 and R. Ragazzoni 3

1 DESPA, Observatoire de Meudon, 5 place Jules Janssen, F-92195 Meudon, France (Boccalet@despa.obspm.fr)
2 Collège de France & Observatoire de Haute Provence F-04870 Saint Michel l'Observatoire, France (Labeyrie@.obs-hp.fr)
3 Astronomical Observatory of Padova, vicolo del'Observatorio 5, I-35122 Padova, Italy (Ragazzoni@astrpd.pd.astro.it)

Received 2 October 1997 / Accepted 22 June 1998


The dark-speckle method (Labeyrie 1995) combines features of speckle interferometry and adaptive optics to provide images of faint circumstellar material. We present preliminary results of observations, and simulations concluding to the feasibility of exo-planet imaging from the ground. Laboratory simulations with an avalanche photodiode indicate the detectability of a stellar companion of relative intensity [FORMULA] at 5 Airy radii from the star. New, more general, expressions for the signal-to-noise ratio and integration time are given. Comparisons with direct long-exposure imaging indicate that the method improves the detectability of circumstellar nebulosity, faint companions and planets.

Key words: planetary systems – stars: low-mass, brown dwarfs – techniques: interferometric – binaries: close - stars: individual: HD 144217

Send offprint requests to: A. Boccaletti@despa.obspm.fr

© European Southern Observatory (ESO) 1998

Online publication: September 8, 1998