We present the first infrared (IR) light curves in the J, H and K bands of δ Lib obtained at different observing runs from 1994 to 1998. These IR light curves, showing a secondary minimum much deeper than in visual bands, have been analysed in order to determine a new set of physical parameters. A new program using the Roche geometry, and stellar

We investigate the diagnostic potential of polarimetric measurements with filtergraph instruments. Numerical simulations are used to explore the possibility of inferring the magnetic field vector, its filling factor, and the thermodynamics of model atmospheres when only a few wavelength measurements are available. These simulations assume the

Through observations and modeling, we demonstrate how the recently discovered large-scale bar in NGC 5248 generates spiral structure that extends from 10 kpc down to 100 pc, fuels star formation on progressively smaller scales, and drives disk evolution. Deep inside the bar, two massive molecular spirals cover nearly 180° in azimuth, show streaming

Gamma-ray and microwave observations of the Cygnus region reveal an intense signal of 1.809 Me line emission, attributed to radioactive decay of 26, that is closely correlated with 53 GHz free-free emission, originating from the ionised interstellar medium. We modelled both emissions using a multi-wavelength evolutionary synthesis code for massive

We determine the extinction curve in the zl=0.83 lens galaxy of the gravitational lens SBS 0909+532 from the wavelength dependence of the flux ratio between the lensed quasar images (zs=1.38) from 3400 to 9200 Å. It is the first measurement of an extinction curve at a cosmological distance of comparable quality to those obtained within the Galaxy

Doppler velocities in the penumbra of a δ-configuration sunspot observed near the limb indicate flows that converge upon the line separating locally positive and negative polarity magnetic field (the polarity inversion line). These flows persist for many hours. Observations of this region with the Advanced Stokes Polarimeter (ASP) reveal a convex