Context. Empirical libraries of stellar spectra are used to classify stars and synthetize stellar populations. MILES is a medium spectral-resolution library in the optical domain covering a wide range of temperatures, surface gravities and metallicities. Aims: We redetermine the atmospheric parameters of these stars in order to improve the

The Isaac Newton Telescope (INT) Photometric H-Alpha Survey (IPHAS) is a 1800 deg2 survey of the Northern Galactic Plane, reaching down to r'˜ 21. We demonstrate how the survey can be used to (1) reliably select classical T Tauri star candidates and (2) constrain the mass accretion rates with an estimated relative uncertainty of 0.6 dex. IPHAS is a

Optical and near-IR observations were carried out with the 0.82mIAC80, 1.23m CAHA, 1.5m OSN and 3.5m CAHA telescopes as follows.

Very High Energy (VHE, E>100 GeV) gamma-rays constitute still nowadays a largely unexplored observing window to the Universe. Due to the opacity of the Earth's atmosphere, the direct observation of these VHE gamma-photons is not possible from ground installations. Moreover, observation from Space by satellites results unfeasible for energies higher

Star formation rate and accumulated stellar mass are two fundamental physical quantities that describe the evolutionary state of a forming galaxy. Two recent attempts to determine the relationship between these quantities, by interpreting a sample of star-forming galaxies at redshift of z˜ 4, have led to opposite conclusions. Using a model galaxy