CCD observations of the gravitational lens system Q0957+561A, B in the BVRI bands are presented in this paper. The observations, taken with the 82 cm IAC-80 telescope at Teide Observatory, Spain, were made from the beginning of 1996 February to 1998 July, as part of an ongoing lens-monitoring program. Accurate photometry was obtained by

We present very accurate individual masses (1.2% relative accuracy) for the two components of Gl 570BC, an interferometric and double-lined spectroscopic binary system. They were obtained from new high accuracy radial velocity and angular separation measurements, analysed together with previously published measurements. From those data we determine

I have studied the relation between the global star formation activity and the bar structure in a sample of isolated barred galaxies. The star formation activity was quantified via the ratio between the IRAS fluxes at 25 mu m and 100 mu m. Two parameters were chosen to define the bar structure: the strength of the bar and the relative projected bar

We derive new spectral Hγ index definitions that are robust age indicators for old and relatively old stellar populations and therefore have great potential for solving the age-metallicity degeneracy of galaxy spectra. To study this feature as a function of age, metallicity, and resolution, we have used a new spectral synthesis model that predicts

The aim of the present work is the detection of solar g-modes, by means of a new observational strategy based on the exploitation of their spatial and temporal properties. The basic data, obtained at the Observatorio del Teide in 1993, consists of daily solar velocity measurements taken continuously and sequentially at six different and symmetric

We use data from the Tenerife 10-, 15- and 33-GHz beam-switching experiments along with the COBE 53- and 90-GHz data to separate the cosmic microwave background (CMB) signal from the Galactic signal, and create two maps at high Galactic latitude. The new multi-MEM technique is used to obtain the best reconstruction of the two channels. The two maps