Proceedings of the International Astronomical Union

Contributed Papers

Results of the NaCo Large Program: probing the occurrence of exoplanets and brown dwarfs at wide orbit

A. Vigana1, G. Chauvina2, M. Bonavitaa3, S. Desideraa3, M. Bonnefoya4, D. Mesaa3, J.-L. Beuzita2, J.-C. Augereaua2, B. Billera4, A. Boccalettia5, E. Brugalettaa6, E. Buenzlia7, J. Carsona8, E. Covinoa9, P. Delormea2, A. Eggenbergera2, M. Feldta4, J. Hagelberga10, T. Henninga4, A.-M. Lagrangea2, A. Lanzafamea6, F. Ménarda2, S. Messinaa6, M. Meyera7, G. Montagniera11, C. Mordasinia4, D. Mouilleta2, C. Moutoua1, L. Mugniera12, S. P. Quanza7, M. Reggiania7, D. Ségransana10, C. Thalmanna13, R. Watersa13 and A. Zurloa1

a1 Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille, France. email:

a2 UJF-Grenoble 1 / CNRS-INSU, IPAG, UMR 5274, Grenoble, F-38041, France

a3 INAF - Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, 35122, Padova, Italy

a4 Max Planck Instiute für Astronomy, Königsthul 17, D-69117 Heidelberg, Germany

a5 LESIA, Observatoire de Paris, CNRS, University Pierre et Marie Curie Paris 6 and University Denis Diderot Paris 7, 5 place Jules Janssen, 92195 Meudon, France

a6 INAF - Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania, Italy

a7 Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland

a8 College of Charleston, Department of Physics & Astronomy, USA

a9 INAF - Osservatorio Astronomico di Napoli, Salita Moiariello 16, 80131 Napoli, Italy

a10 Geneva Observatory, Univ. of Geneva, Chemin des Mailettes 51, 1290, Versoix, Switzerland

a11 Observatoire de Haute-Provence, CNRS/OAMP, 04870 Saint-Michel-l'Observatoire, France

a12 Onera - The French Aerospace Lab, 92322, Chatillon, France

a13 University of Amsterdam, Postbus 94249, 1090 GE, Amsterdam, The Netherlands


Over the past decade, a growing number of deep imaging surveys have started to provide meaningful constraints on the population of extrasolar giant planets at large orbital separation. Primary targets for these surveys have been carefully selected based on their age, distance and spectral type, and often on their membership to young nearby associations where all stars share common kinematics, photometric and spectroscopic properties. The next step is a wider statistical analysis of the frequency and properties of low mass companions as a function of stellar mass and orbital separation. In late 2009, we initiated a coordinated European Large Program using angular differential imaging in the H band (1.66 μm) with NaCo at the VLT. Our aim is to provide a comprehensive and statistically significant study of the occurrence of extrasolar giant planets and brown dwarfs at large (5-500 AU) orbital separation around ~150 young, nearby stars, a large fraction of which have never been observed at very deep contrast. The survey has now been completed and we present the data analysis and detection limits for the observed sample, for which we reach the planetary-mass domain at separations of ≳50 AU on average. We also present the results of the statistical analysis that has been performed over the 75 targets newly observed at high-contrast. We discuss the details of the statistical analysis and the physical constraints that our survey provides for the frequency and formation scenario of planetary mass companions at large separation.


  • instrumentation: adaptive optics;
  • instrumentation: high angular resolution;
  • stars: imaging;
  • methods: statistical