Aims.Infrared and optical photometric and spectroscopic observations of the symbiotic nova RR Tel are used to study the effects and properties of dust in symbiotic binaries containing a cool Mira component, as well as showing "obscuration events" of increased absorption, which are typical for such Miras. Methods: .A set of photometric observations

The Ca IR triplet lines are a good candidate for observing chromospheric magnetic fields. Simulations of the lines in the high-beta regime, spectropolarimetric observations and inversions of observations give insight to their usabilitysuitability in observing QS magnetic fields and dynamics. Propagating waves are clearly visible in the simulations

We present a progress report on a project aimed at determining the absolute proper motion of the Small Magellanic Cloud (SMC), with respect to background Quasi Stellar Objects (QSOs) that can be used as fiducial reference points (Anguita et al. 2000, Pedreros et al. 2002, Pedreros et al. 2005). The motions thus derived, when combined with existing

We present optical and infrared monitoring of the 2005 outburst of the halo black hole X-ray transient XTE J1118+480. We measured a total outburst amplitude of ~5.7+/-0.1 mag in the R band and ~5 mag in the infrared J, H, and Ks bands. The hardness ratio HR2 (5-12 keV:3-5 keV) from the RXTE ASM data is 1.53+/-0.02 at the peak of the outburst

We present a detailed surface density analysis of a large sample of simulated collisionless mergers of disc galaxies with bulges (mass ratios 1:1, 2:1, 3:1, 4:1 and 6:1) and without bulges (mass ratios 1:1 and 3:1). A dissipative component was not included. The randomly projected remnants were fit with a single Sérsic function and a Sérsic function

A spectroscopic analysis is presented, where elliptical galaxies in Hickson Compact Groups (HCG) are compared with their counterparts in the field. The stellar population study shows that low-mass galaxies in HCGs present an enhanced [Mg/Fe] abundance ratio, interpreted as a relic of an event which truncated their star formation