Context. Empirical libraries of stellar spectra play an important role in different fields. For example, they are used as reference for the automatic determination of atmospheric parameters, or for building synthetic stellar populations to study galaxies. The CFLIB (Coudé-feed library, Indo-US) database is at present one of the most complete

Context. The small radius and high density of CoRoT-7b implies that this transiting planet belongs to a different species than all transiting planets previously found. Current models suggest that this is the first transiting rocky planet found outside the solar system. Given that the planet orbits a solar-like star at a distance of only 4.5 R*, it

In this study, the interaction of stellar wind plasma with the exosphere and possibly with the planetary magnetospheric environment of close-in rocky exoplanets is investigated. In particular, we focus on the “super-Earth” CoRoT-7b, which has been recently discovered by the CoRoT space observatory. The physical properties of such a planet, with an

For nearly a century Black holes have been a hot topic, a physical singularity or simply a flawed, all be it brilliant, mathematical concept? Fundamental proof of the existence of black holes lies in the proof of the existence of their event horizons. One such proof lies in the comparison of the X-ray luminosities of black hole and neutron star X

Short period binary white dwarfs may merge within a Hubble time due to gravitational wave radiation. We have begun a targeted survey to find merging white dwarfs systems, and our first results have tripled the number of known merging white dwarf systems. Our sample includes systems with orbital periods as short as 1 hr and with merger times less

In addition to the well-known 11-year solar cycle, the Sun's magnetic activity also shows significant variation on shorter time scales, e.g. between one and two years. We observe a quasi-biennial (2-year) signal in the solar p-mode oscillation frequencies, which are sensitive probes of the solar interior. The signal is visible in Sun-as-a-star data