High-resolution observations of sunspots have revealed the existence of dark cores inside the bright filaments of the penumbra. Here we present the stationary solution of the heat transfer equation in a stratified penumbra consisting of nearly horizontal magnetic flux tubes embedded in a stronger and more vertical field. The tubes and the external

This paper reviews some recent advances in the development and application of polarized radiation diagnostics to infer the mean magnetization of the quiet solar atmosphere, from the near equilibrium photosphere to the highly non-equilibrium upper chromosphere. In particular, I show that interpretations of the scattering polarization observed in

Full-Stokes spectropolarimetric data (in the 10830 Å region) of an active region filament were obtained in July 2005 using the Tenerife Infrared Polarimeter instrument. The polarization profiles in the filament show Zeeman-like signatures. Milne-Eddington inversions were performed to infer the chromospheric magnetic field, inclination, azimuth

We present results from ongoing science projects conducted by members of the Faulkes Telescope (FT) team and Las Cumbres Observatory Global Telescope (LCOGT). Many of these projects incorporate observations carried out and analysed by FT users, comprising amateur astronomers and schools. We also discuss plans for the further development of the

One of the tasks carried out by the Astroparticle Physics Group of the IAC is the analysis of objects observed by the MAGIC telescope looking for very high energy gamma-ray emission. The main goal of these observations is to search for acceleration of cosmic rays sites and the identification of accelerated species. We have analyzed MAGIC data of

We have undertaken a study of the nature of red galaxies at low and intermediate redshifts in the GOYA photometric survey. A new photometric index based on apparent magnitudes has been obtained to separate red galaxies dominated by old populations from those dominated by star formation. A two-component mass code has been used to estimate the