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

We have computed the Band Area Ratio (BAR) and Band I Center parameters, following the method by Cloutis et al. (1986) and Gaffey et al. (1993) for all the existent visible and near-infrared spectra of near-Earth asteroids (NEAs), main belt asteroids (MBs) and meteorites (Duffard et al.2005). For the NEAs we have grouped observations from NEOSS (de

Aims:We present an analysis of high resolution spectra in the J band of five ultra cool dwarfs from M6 to L0. Methods: We make use of a new ab initio water vapour line list and existing line lists of FeH and CrH for modelling the observations. Results: We find a good fit for the Mn I 12 899.76 Å line. This feature is one of the few for which we