New dispersive elements providing relative high resolution (R=2200) have been recently incorporated in the near infrared spectrograph LIRIS. These elements are founded on a rather novel design based on a diffractive pattern engraved in fused silica, which is placed between two prisms. These new components are pushing forward the scientific

We present evidence of the coexistence of either an AGN or an ultraluminous X-ray source, together with a young superstellar cluster, in the central 3 pc of NGC 4303. The galaxy contains a low-luminosity AGN and hosts a number of starburst regions in a circumnuclear spiral, as well as in the nucleus itself. A high spatial resolution Chandra image

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A spectral ratio, similar to that of von der Lühe (1984), is proposed to derive information on the degradation of the mean granular power spectrum at a position outside the disk centre. It has the advantage that the modulation transfer function is obtained directly from the data, without making any assumption on turbulence theory to describe the

The magnetic fields of the quiet Sun cover at any time more than 90% of its surface and their magnetic energy budget is crucial to explain the thermal structure of the solar atmosphere. One of the possible origins of these fields is the action of the local dynamo in the upper convection zone of the Sun. Existing simulations of the local solar

The numerical simulation method for variable white dwarfs of Ising & Koester (2001) is extended to variable DB stars (DBVs or V777 Herculis stars). We find the same general behavior of nonlinear effects, with a sinusoidal light-curve at small amplitudes, strongly non-sinusoidal variations at intermediate amplitudes and a change back to smaller and