A&A 493, L21-L25 (2009)
A probable giant planet imaged in the Pictoris disk
VLT/NaCo deep L -band imagingA.-M. Lagrange1, D. Gratadour2, G. Chauvin1, T. Fusco3, D. Ehrenreich1, D. Mouillet1, G. Rousset2, 3, D. Rouan2, F. Allard4, É. Gendron2, J. Charton1, L. Mugnier3, P. Rabou1, J. Montri3, and F. Lacombe2
1 Laboratoire d'Astrophysique de l'Observatoire de Grenoble, Université Joseph Fourier, CNRS (UMR 5571), BP 53, 38041 Grenoble, France
2 Laboratoire d'Études Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris, CNRS (UMR 8109), Université Pierre et Marie Curie, Université Paris-Diderot, 5 place Jules Janssen, 92190 Meudon, France
3 Office National d'Études et de Recherches Aérospatiales, 29 avenue de la Division Leclerc, 92322 Châtillon, France
4 Centre de Recherche Astronomique de Lyon, CNRS (UMR 5574), Université Claude Bernard, École Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 7, France
Received 10 November 2008 / Accepted 18 November 2008
Context. Since the discovery of its dusty disk in 1984, Pictoris has become the prototype of young early-type planetary systems, and there are now various indications that a massive Jovian planet is orbiting the star at ~10 AU. However, no planets have been detected around this star so far.
Aims. Our goal was to investigate the close environment of Pic, searching for planetary companion(s).
Methods. Deep adaptive-optics L'-band images of Pic were recorded using the NaCo instrument at the Very Large Telescope.
Results. A faint point-like signal is detected at a projected distance of 8 AU from the star, within the northeastern extension of the dust disk. Various tests were made to rule out possible instrumental or atmospheric artefacts at a good confidence level. The probability of a foreground or background contaminant is extremely low, based in addition on the analysis of previous deep HST images. Its L'=11.2 apparent magnitude would indicate a typical temperature of ~1500 K and a mass of ~8 . If confirmed, it could explain the main morphological and dynamical peculiarities of the Pic system. The present detection is unique among A-stars by the proximity of the resolved planet to its parent star. Its closeness and location inside the Pic disk suggest a formation process by core accretion or disk instabilities rather than binary-like formation processes.
Key words: instrumentation: adaptive optics -- stars: early-type -- stars: planetary systems -- stars: individual: Pic
© ESO 2009