Cool Stars 14 - Submitted Abstract # 378
This version created on 06 October 2006

Search for substellar companions in the Tucana and Beta Pictoris moving groups

Markus Kasper, ESO
Daniel Apai, Steward Observatory
Markus Janson, MPIA
Wolfgang Brandner, MPIA

Radial velocity searches provide evidence that giant extrasolar planets are 
common, but the detection space is limited to only a few astronomical units 
from the stars. In order to close this gap, we used the Adaptive Optics system 
NACO at the VLT for a deep (~20 minutes exposure time per target) L'-band (3.8 
microns) survey of a sample of close-by young stars. The chosen observation 
wavelength is very well suited for very high contrast imaging of close 
companions due to the high Strehl ratios (~70%) and the favorable contrast 
between star and substellar companion making this survey unique. The goal was 
to detect substellar companions to these stars at distances as close as 5-20 AU 
and ultimately to detect giant extrasolar planets down to a few Jupiter masses, 
to measure their frequency, and - by comparison with models - determine their 
physical properties. The poster presents the results obtained on the 19 stars 
that have been surveyed during the VLT observing periods 73 and 74. 

----------------------------------