Aims:I deduced a 3D sunspot model that is in full agreement with spectropolarimetric observations, in order to address the question of a possible penumbral heating process by the repetitive rise of hot flow channels. Methods: I performed inversions of spectropolarimetric data taken simultaneously in infrared (1.5 μm) and visible (630 nm) spectral

We report results from our Spitzer GO-1 program on IRS spectroscopy of a large sample of Luminous Infrared Galaxies and quasars selected from the European Large Area ISO Survey (ELAIS). The selected ELAIS sources have a wide multi-wavelength coverage, including ISOCAM, ISOPHOT, IRAC and MIPS (from SWIRE), and optical photometry. Here we present the

La Heliosismología es la interpretación de los modos propios del Sol. La detección de millones de modos propios ha revolucionado nuestro conocimiento del interior solar. Ello ha permitido determinar la velocidad del sonido desde su superficie hasta casi el mismo núcleo del Sol. Además ha proporcionado una medida de la rotación diferencial de la

Stellar variability types are assigned on the basis of lightcurve appearance, which often remains unchallenged without further observational evidence. VSOP (Variable Star One-shot Project) is a large international collaboration, which has so far obtained spectra of more than 500 stars during the past year. Operationally this program is a completely

We report about very high energy (VHE) γ-ray observations of the Crab Nebula with the MAGIC telescope. The γ-ray flux from the nebula was measured between 60 GeV and 9 TeV. The energy spectrum can be described by a curved power law dF/dE=f0(E/300 GeV)[a+blog10(E/300GeV)] with a flux normalization f0 of (6.0+/-0.2stat)×10-10 cm-2 s-1 TeV-1, a=-2.31+

Aims:We calculate the bounds on the variation in the fine structure constant at the time of primordial nucleosynthesis and at the time of neutral hydrogen formation. We used these bounds and other bounds from the late universe to test the Bekenstein model. Methods: We modified the Kawano code, CAMB, and CosmoMC to include the possible variation in