We observed the new X-ray transient, MAXI J0556-332 (ATel #3102, #3103, #3104, #3106, #3110, #3112) with the Faulkes Telescope South on 17 and 18 January 2011 (MJD 55578.4 and 55579.5). On each date, three 200-sec exposures were taken; one each in Bessel V, R, and I bands, totalling six images. The suggested optical counterpart (ATel #3103) was

We report on the discovery of a relation between the stellar mass M* of early-type galaxies (hereafter ETGs), their shape, as parameterized by the Sersic index n, and their stellar mass-to-light ratio M*/L. In a three-dimensional log space defined by these variables, the ETGs populate a plane surface with small scatter. This relation tells us that

We report new observations of the intermediate-frequency peaked BL Lacertae object 3C 66A with the MAGIC telescopes. The data sample we use were taken in 2009 December and 2010 January, and comprises 2.3 hr of good quality data in stereoscopic mode. In this period, we find a significant signal from the direction of the blazar 3C 66A. The new MAGIC

Most of the visible light coming from the Sun originates in the solar photosphere. Numerical simulations are a common tool to study the solar atmosphere starting from the basic laws of physics and few additional assumptions. This thesis presents results of three-dimensional radiative magnetohydrodynamic simulations of the quiet-sun, plage and

We study the coupling of magneto-acoustic waves to Alvén waves using 2.5D numerical simulations. In our experiment, a fast magnetoacoustic wave of a given frequency and wavenumber is generated below the surface. The magnetic field in the domain is assumed homogeneous and inclined. The efficiency of the conversion to Alfvén waves near the layer of

We present a near-IR and optical spectrophotometric characterization of the stellar population of Sh2-152, as part of our MASGOMAS project. Using new broad band photometry (J, H and K_S) for the cluster and a control field, we have constructed CMD in order to select OB-candidates for H and K spectroscopy. Also, we have obtained the cluster mass