Volume 520, September-October 2010
|Number of page(s)||4|
|Published online||23 September 2010|
Letter to the Editor
Deep near-infrared interferometric search for low-mass companions around β Pictoris*
Institut d'Astrophysique et de Géophysique, Université de Liège, 17 Allée du Six Août, 4000 Liège, Belgium e-mail: email@example.com
2 LAOG–UMR 5571, CNRS and Université Joseph Fourier, BP 53, 38041 Grenoble, France
3 INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
4 European Southern Observatory, Casilla 19001, Santiago 19, Chile
Accepted: 3 September 2010
Aims. We search for low-mass companions in the innermost region (<300 mas, i.e., 6 AU) of the β Pic planetary system.
Methods. We obtained interferometric closure phase measurements in the K-band with the VLTI/AMBER instrument used in its medium spectral resolution mode. Fringe stabilization was provided by the FINITO fringe tracker.
Results. In a search region of between 2 and 60 mas in radius, our observations exclude at 3σ significance the presence of companions with K-band contrasts greater than 5×10-3 for 90% of the possible positions in the search zone (i.e., 90% completeness). The median 1σ error bar in the contrast of potential companions within our search region is 1.2×10-3. The best fit to our data set using a binary model is found for a faint companion located at about 14.4 mas from β Pic, which has a contrast of 1.8×10-3 ± 1.1×10-3 (a result consistent with the absence of companions). For angular separations larger than 60 mas, both time smearing and field-of-view limitations reduce the sensitivity.
Conclusions. We can exclude the presence of brown dwarfs with masses higher than 29 MJup (resp. 47 MJup) at a 50% (resp. 90%) completeness level within the first few AUs around β Pic. Interferometric closure phases offer a promising way to directly image low-mass companions in the close environment of nearby young stars.
Key words: stars: individual: β Pic / planets and satellites: detection / techniques: interferometric / planetary systems
© ESO, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.