Ground-based infrared imaging search for sub-stellar companions next to young nearby stars

Neuhäuser, R., Guenther, E., Brandner, W., Alves, J., Eckart, A., Ott, T., Huélamo, N., Fernández, M., and Cuby, J.-G.
Birth and Evolution of Binary Stars, Poster Proceedings of IAU Symposium No. 200 on The Formation of Binary Stars, held 10-15 April, 2000, in Potsdam, Germany. Edited by Bo Reipurth and Hans Zinnecker, 2000, p. 41.


We report first results from our ground-based infrared imaging search for sub-stellar companions next to young (up to 100 Myrs) nearby (up to 75 pc) stars, where companions should be well separated from the central stars and still relatively bright due to ongoing accretion and/or contraction. Among our targets are all members of the TW Hya association, as well as other binary and single young stars either discovered recently among ROSAT sources (some of which as yet unpublished) or known before. Our observations are performed mainly with SOFI and SHARP at the ESO 3.5m NTT on La Silla and with ISAAC at the ESO 8.2m Antu (VLT-UT1) on Cerro Paranal, all in the H- and K-bands. We present direct imaging data of a faint object detected next to TWA-7 which, if at the same age and distance as the central star, could be an object with only a few Jupiter masses.