We report Stokes vector observations of solar spicules and a prominence in the He I 1083 nm multiplet carried out with the Tenerife Infrared Polarimeter. The observations show linear polarization profiles that are produced by scattering processes in the presence of a magnetic field. After a careful data reduction, we demonstrate the existence of

Stars are generally spherical, yet their gaseous envelopes often appear nonspherical when ejected near the end of their lives. This quirk is most notable during the planetary nebula phase, when these envelopes become ionized. Interactions among stars in a binary system are suspected to cause the asymmetry. In particular, a precessing accretion disk

Pluto and Eris are icy dwarf planets with nearly identical sizes, comparable densities and similar surface compositions as revealed by spectroscopic studies. Pluto possesses an atmosphere whereas Eris does not; the difference probably arises from their differing distances from the Sun, and explains their different albedos. Makemake is another icy

In this review, we look back upon the literature, which had the GREGOR solar telescope project as its subject including science cases, telescope subsystems, and post-focus instruments. The articles date back to the year 2000, when the initial concepts for a new solar telescope on Tenerife were first presented at scientific meetings. This

La formación estelar es el factor más importante que controla la evolución de las galaxias, con la posible excepción de la interacción galaxia-galaxia, y se ha convertido en uno de los campos más investigados y discutidos en la astronomía actual. Los detalles de la interacción entre el contenido de gas de las galaxias y los procesos que disparan la

El proyecto MASGOMAS (``MAssive Stars in Galactic Obscured MAssive clusterS'') tiene como objetivo descubrir, observar y caracterizar físicamente cúmulos jóvenes, masivos (varios miles de masas solares) y altamente enrojecidos, pertenecientes a nuestra Galaxia, en especial aquellos cuya masa total excede 10000 masas solares. Estos cúmulos, de los