Theoretical models are developed to account for the asymmetries observed by Stenflo et al. (1984) in the Stokes V profiles of solar faculae. The approximate dependence of Stokes V on magnetic and velocity fields in the line of sight is characterized under the assumption of local thermodynamic equilibrium, and empirical growth curves for the zero

We report on the results from the observations in the very high energy band (VHE; Eγ>=100 GeV) of the black hole X-ray binary (BHXB) Cygnus X-1. The observations were performed with the MAGIC telescope, for a total of 40 hr during 26 nights, spanning the period between 2006 June and November. Searches for steady γ-ray signals yielded no positive

A very high energy (VHE) γ-radiation was detected from a flat spectrum radio quasar (FSRQ) 4C 21.35 (PKS1222+21) by MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes on June 17 th 2010. 4C 21.35 is only the 3 rd FSRQ detected in VHE γ-rays. With its hard spectrum (Γ = 2.72+/-0.34) with no apparent cut-off at energies below 130 GeV and an

The KIS/IAA Vector Imaging Polarimeter (VIP) is a new instrument for two-dimensional spectropolarimetry of the solar atmosphere. It is used with TESOS, the triple etalon Fabry-Perot interferometer installed at the German Vacuum Tower Telescope of Observatorio del Teide (Tenerife, Spain). The polarimeter is based on a pair of nematic liquid crystal

We describe a proposal for a public IR variability survey of the entire Milky Way Bulge and a large portion of the Southern Galactic Plane with VISTA at ESO Paranal Observatory. The survey will take about 180 nights, covering 5×10^8 point sources within an area of about 600 sq deg, including 40 known globular clusters and more than one hundred

We present V and R photometry of 16 Kuiper belt objects (KBOs) from the 3.6-m Telescopio Nazionale Galileo and the Complejo Astronómico El Leoncito 2.1-m telescope. We find a wide dispersion in the (V-R) colors of the objects, indicating nonuniform surface properties. If we assume near constant albedos, there does not appear to be a general trend