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. ----------------------------------