A. -M. Lagrange, K. De Bondt, N. Meunier, M. Sterzik, H. Beust, F. Galland
Context. The {\beta} Pictoris system with its debris disk and a massive giant
planet orbiting at \simeq 9 AU represents an ideal laboratory to study giant
planet formation and evolution as well as planet-disk interactions. {\beta} Pic
b can also help testing brightness-mass relations at young ages. Other planets,
yet undetected, may of course be present in the system. Aims. We aim at putting
direct constrains on the mass of {\beta} Pic b and at searching for additional
jovian planets on orbits closer than typically 2 AU. Methods. We use high
precision Harps data collected over 8 years since 2003 to measure and analyse
{\beta} Pic radial velocities. Results. We show that the true mass of {\beta}
Pic b is less than 10, 12, 15.5, 20 and 25 MJup if orbiting respectively at 8,
9, 10, 11 and 12 AU. This is the first direct constraint on the mass of an
imaged planet. The upper mass found is well in the range predicted by
brightness-mass relations provided by current "hot start" models. We also
exclude the presence of giant planets more massive than 2.5 MJup with periods
less than 100 days (hot Jupiters), more massive than 9 MJup for periods in the
range 100-500 days. In the 500-1000 day range, the detection limit is in the
brown dwarf domain. Beyond the intrinsic interest for {\beta} Pic, these
results show the possibilities of precise RV measurements of early type,
rapidly rotating stars.
View original:
http://arxiv.org/abs/1202.2579
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