We present a comprehensive study of the observational dependence of the mass-loss rate in stationary stellar winds of hot massive stars on the metal content of their atmospheres. The metal content of stars in the Magellanic Clouds is discussed, and a critical assessment is given of state-of-the-art mass-loss determinations of OB stars in these two

This paper reports on our new findings from the International Time Program observations at the Canaries islands, Spain, in July 2005. We have found small-scale photospheric events with extremely red-shifted Stokes V signals in sunspot moat regions. A preliminary estimate of the physical conditions for an observed Stokes V profile indicates the

Results concerning the dependence of photometric and radial velocity amplitudes on metallicity are presented based on about 200 Galactic classical Cepheids pulsating in the fundamental mode. The Galactic distribution of the [Fe/H] value of Cepheids is also studied. We show that the photometric amplitude ratio AI/AV is independent of metallicity

The characterization of the vertical turbulence distribution on an astronomical site should be based on statistical behaviour, as it is required for other parameters in site testing. We present the statistical results of the optical-turbulence profiles at the Roque de los Muchachos and Teide observatories at the Canary Islands (Spain). The data

Aims:We study the two-dimensional distribution and kinematics of the stellar and gaseous components in the centre of the blue compact dwarf galaxy He 2-10. The aim is to compare the kinematics of gas and stars in order to determine whether they are consistent with one another, or if stars and gas can be decoupled due to gravitational perturbations

We have started a near-infrared spectroscopic study of the Veritas asteroid family. This family is of particular interest for several reasons: 1) This 8.2 million-year-old family contains fresh fragments of a primitive parent body (Nesvorney et al., 2005). 2) Interplanetary dust from the Veritas collision makes up over 25% of interplanetary dust