The aim of the work is to increase the database of the fundamental stellar parameters and to test stellar structure and evolution. For this purpose, photometric observations of many binary systems have been collected at various telescopes (60 cm and 152 cm in Loiano and the 6m BAT of SAO in Russia) in order to derive their light curves. In addition, many data have been collected for precise timing of the light minima of systems exibiting apsidal motion (DR Vul, V380 Cyg, RR Lyn, AK Her, ER Vul, BF Aur) whose determination can be correlated to the mass distribution in the stellar interiors.
With the 152 cm telescope in Loiano - equipped with the Two-heads photometer - we collected the light curves of two W UMa-type systems XY Leo and RW Com. With the same telescope (together with the 6m BAT, that collected also some spectra) we observed the very interesting PCV NN Serpentis.
The light curve analyses are performed adopting computer codes (Wilson-Devinney, WINK, EBOPC) based on geometric and physical models which account for the various effects acting on the systems components.
In the year 2001 our work has proceeded: a) implementing the Wilson-Price computer program (Barone et al. 1988) in the Windows environment, operating a new CPU (AMD Athlon XP 1800+) which reduces the computing time down to 10 percent with respect to a VMS VAXstat 4000/90. This code is based on the Wilson-Devinney (1971) model, but its fitting procedure is based on the "controlled random search" (Price 1976); b) testing the code in two ways: solving light curves whose parameters were already obtained through the "classical" Wilson-Devinney code and solving light curves synthesized from a set of parameters. In both situations our results are very satisfactory.
We have also undertaken the analysis of our light curve of the W Uma-type spotted system RW Com.
This work is in collaboration with Guarnieri, Bartolini, Piccioni and Cosentino (Univ. Bologna), Beskin (SAO), Milano (Univ. Napoli) and Barone (Univ. Salerno).