A new stellar library developed for stellar population synthesis modelling is presented. The library consists of 985 stars spanning a large range in atmospheric parameters. The spectra were obtained at the 2.5‐m Isaac Newton Telescope and cover the range λλ 3525–7500 Å at 2.3 Å (full width at half‐maximum) spectral resolution. The spectral resolution, spectral‐type coverage, flux‐calibration accuracy and number of stars represent a substantial improvement over previous libraries used in population‐synthesis models.

We present a homogeneous set of stellar atmospheric parameters (T eff , log g, [Fe/H]) for MILES, a new spectral stellar library covering the range λλ 3525-7500 Å at 2.3 Å (FWHM) spectral resolution. The library consists of 985 stars spanning a large range in atmospheric parameters, from super-metal-rich, cool stars to hot, metal-poor stars. The spectral resolution, spectral type coverage and number of stars represent a substantial improvement over previous libraries used in population synthesis models. The atmospheric parameters that we present here are the result of a previous, extensive compilation from the literature. In order to construct a homogeneous data set of atmospheric parameters we have taken the sample of stars of Soubiran, Katz & Cayrel, which has very well determined fundamental parameters, as the standard reference system for our field stars, and have calibrated and bootstrapped the data from other papers against it. The atmospheric parameters for our cluster stars have also been revised and updated according to recent metallicity scales, colour-temperature relations and improved set of isochrones.

Aims. Extensive photometry of RR Lyr was obtained over a 421-day interval in 2003-2004, covering more than 10 Blazhko cycles in a multisite campaign. The length and density of this data set allow for a detailed analysis. Methods. We used Fourier techniques to study RR Lyr's behavior over the pulsation and the Blazhko cycle. We propose a twofrequency model for decomposing the frequency spectrum. Results. The light variations were fitted with the main radial frequency, its harmonics up to 11th order, and the detected triplet frequencies. No significant quintuplet components were found in the frequency spectrum. Given the total time span of the measurements, we can now unambiguously conclude that the Blazhko period has become notably shorter than the previously known value of 40.8 days, whereas the main pulsation period remained roughly the same. Changes in the modulation period have been reported for other well-studied Blazhko variables. They challenge the explanations for the Blazhko effect which link the modulation period directly to the rotation period. The new photometry reveals an interval in the pulsation cycle of RR Lyr during which the star's intensity barely changes over the Blazhko cycle. This interval occurs during the infalling motion and between the supposed phases of the early and the main shock. The data also permit a more detailed study of the light curve shape at different phases in the Blazhko period through Fourier parameters.

Abstract.A sample of W UMa-type binaries which were discovered by the HIPPARCOS satellite was constructed with the aid of well defined selection criteria described in this work. The selection process showed up that several systems of which the variability types have been assigned as EB in HIPPARCOS catalogue are genuine contact binaries of W UMa-type. The light curves of the 64 selected systems based on HIPPARCOS photometry were analyzed with the aid of light curve synthesis method by Rucinski and their geometric elements (namely mass ratio q, degree of contact f , and orbital inclination i) were determined. The solutions were obtained for the first time for many of the systems in the sample and would be a good source for their future light curve analyses based on more precise follow-up observations.