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Stellar rotation and variability in the Orion Nebula Cluster
A wide field imager attached to the MPG/ESO 2.2 m telescope on La Silla has been used to monitor the Orion Nebula Cluster on 45 nights between 25 Dec. 1998 and 28 Feb. 1999. Ninety-two images were
Discovery of Young, Isolated Planetary Mass Objects in the σ Orionis Star Cluster
We present the discovery by optical and near-infrared imaging of an extremely red, low-luminosity population of isolated objects in the young, nearby stellar cluster around the multiple, massive star
The Substellar Mass Function in σ Orionis
We combine results from imaging searches for substellar objects in the σ Orionis cluster and follow-up photometric and spectroscopic observations to derive a census of the brown dwarf population in a
Hubble Space Telescope/STIS Spectroscopy of the Optical Outflow from DG Tauri: Indications for Rotation in the Initial Jet Channel*
We have carried out a kinematical, high angular resolution (~01) study of the optical blueshifted flow from DG Tau within 05 from the source (i.e., 110 AU when deprojected along this flow). We
Imaging and Kinematic Studies of Young Stellar Object Jets in Taurus
We report on an imaging and kinematic study of the jets and outflows emanating from DG Tau, DG Tau B, FS Tau B, T Tau, and CoKu Tau 1. The kinematic data are based on proper-motion measurements and
Rotational evolution of low mass stars: The case of NGC 2264 ?
Our study is based on an extensive photometric monitoring program in the young (2-4 Myr) open cluster NGC 2264 by Lamm et al. (2004a). This program resulted in a sample of 405 periodic variables
Spatial and kinematic properties of the forbidden emission line region of T Tauri stars
We have carried out a long-slit spectroscopic survey for 38 T Tauri stars (TTSs) to study the spatial and kinematic properties of their forbidden emission line (FEL) regions. With these observations
Pre-main sequence spectroscopic binaries suitable for VLTI observations ,
Context. A severe problem for research in star-formation is that the masses of young stars are almost always estimated from evolutionary tracks alone. Since the tracks published by different groups
A rotational and variability study of a large sample of PMS stars in NGC 2264
We present the results of an extensive search for periodic and irregular variable pre-main sequence (PMS) stars in the young (2-4 Myr) open cluster NGC 2264, based on photometric monitoring using the
A Search for Hot Massive Extrasolar Planets around Nearby Young Stars with the Adaptive Optics System NACO
We report on a survey devoted to the search of exoplanets around young and nearby stars carried out with NACO at the VLT. The detection limit for 28 among the best available targets versus the