A&A Supplement Series, Vol. 125, October I 1997, 175-182

Received July 26, 1995; accepted December 19, 1996

A stellar coronograph for the COME-ON-PLUS adaptive optics system

I. Description and performance

J.-L. Beuzit - D. Mouillet - A.-M. Lagrange - J. Paufique

Send offprint request: J.-L. Beuzit

  Laboratoire d'Astrophysique de l'Observatoire de Grenoble, UMR 5571, Université J. Fourier, BP. 53, F-38041 Grenoble Cedex 9, France
  DESPA, Observatoire de Paris, URA 264, Place J. Janssen, F-92195 Meudon Cedex, France

Abstract:

The detection of faint emissions very close to much brighter objects is required in several different fields of astrophysics, for example in the search for planetary disks. We present here a coronograph that we built to work with COME-ON-PLUS, the ESO adaptive optics system, high angular resolution being of key importance in allowing observations close to a central, occulted object. The first results are presented and analyzed in order to establish the performance of this instrument in terms of contrast and detectability of faint emissions close to a central star.

keywords: atmospheric effects -- methods: data analysis -- instrumentation: miscellaneous -- stars:circumstellar matter

• 1. Introduction
• 2. Need for an adaptive optics coronograph
• 3. Description of the COME-ON-PLUS
  coronograph
• 4. Data reduction
• 5. Performances of the coronograph
• 6. Comparison with expected performance and other systems
• 7. Conclusion and perspectives
• References