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 differ, it is often only possible to give a rough estimate of the masses of young stars. It is thus crucial to test and calibrate the tracks. Up to now

We explore correlations between visual extinction and polarization along the western side of the Infrared Astronomical Satellite (IRAS) Vela Shell using a published polarimetric catalog of several hundred objects. Our extinction maps along this ionization front (I-front) find evidence of clumpy structure with typical masses between 1.5 and 6 Msolar

Driven by the incomplete understanding of the formation of gas giant extrasolar planets and of their mass-radius relationship, several ground-based, wide-field photometric campaigns are searching the skies for new transiting extrasolar gas giants. As part of the Trans-atlantic Exoplanet Survey (TrES), in 2003/2004 we monitored approximately 30,000

OTELO, the key OSIRIS science project is a deep emission line object survey to be performed with the OSIRIS Tunable Filters in selected atmospheric windows relatively free of sky emission lines (Cepa et al. 2006; Cepa et al. 2005).

We present a preliminary analysis of public, deep (200 ksec.) Chandra/ACIS observations of three fields comprising the original Groth-Westphal strip (GWS), gathered from the Chandra Data Archive, combined with optical BVRI data from our broadband survey carried out with the 4.2-m WHT at La Palma. This work has been performed in the framework of the

Based on the GOYA Photometric Survey of the HST Groth-Westphal strip, we present galaxy number counts in B and Ks bands together with a model that simultaneously reproduces the counts and that does not need to add an extra population of blue dwarf galaxies to reproduce the blue excess of the counts at faint magnitudes.