The discovery of ɛ Indi Ba, Bb, a binary brown dwarf system very close to the Sun, makes possible a concerted campaign to characterise the physical parameters of two T dwarfs. Recent observations suggest substellar atmospheric and evolutionary models may be inconsistent with observations, but there have been few conclusive tests to date. We

Extreme Ultraviolet (EUV) and X-ray emission is of great importance in several phenomena related to the formation of planetary systems and the atmospheres of planets. The atmospheric composition, and the mass of an exoplanet, are partly dependent on the X-ray and EUV radiation received during the first stages of formation and even during main

Evolutionary tracks are of key importance for the understanding of star formation. Unfortunately, tracks published by various groups differ so that it is fundamental to test them observationally. In order to do this, we derived the masses of the two components of the Pre-Main Sequence (PMS) binary HD113449 by combining radial velocity (RV)

Mid-infrared (mid-IR) imaging at resolutions of 300mas of the central kpc region of 13 nearby, well-known active galaxies is presented. The bulk of the mid-IR emission is concentrated on an unresolved central source within a size of less than 5-130pc, depending on the object distance. Further resolved emission is detected in 70 per cent of the

Context. CoRoT, the pioneer space-based transit search, steadily provides thousands of high-precision light curves with continuous time sampling over periods of up to 5 months. The transits of a planet perturbed by an additional object are not strictly periodic. By studying the transit timing variations (TTVs), additional objects can be detected in

NGC 2808 is one of the globular clusters containing multiple stellar populations in our Galaxy. The cluster color-magnitude diagram contains two extra sequences blueward of the main cluster ridge-line. Stars on these sequences appear to be enhanced in Helium up to Y=0.40. The origin of these stars is still mysterious although they are believed to