Abstract. New photometric data set of the early type contact binary V 382 Cyg have been analyzed with emphasis on determining the photometric mass ratio of the system. The result (q = 0.68) supports the value given by Popper & Hill (1991). A study of the system using new data shows a period increase of about 3.28 s per century, which corresponds to a very large rate ∼ 5.0 10 −6 M /yr of mass transfer from the less massive to the more massive component under the conservative mass transfer hypothesis.

Abstract. New light curves and available times of minima of a β Lyr system EG Cep were analysed to deduce more information on the nature of the system. The main U-shaped (O − C) variation was interpreted in terms of the mass transfer and mass loss in the system. The same variation was also considered as a part of a sinusoidal variation and thus interpreted in terms of a light-time effect due to an unseen component in the system. New B and V light curves were analyzed with different fitting procedures, and there is general agreement that both stars must be very close to each other and to stability limits. A model that fits all the data well has a near main sequence primary and a secondary star that is overflowing matter towards it. This secondary is also reasonably close to main sequence conditions. The configuration thus appears to be a (relatively uncommon) 'Case A' type evolving Algol and raises interesting questions about such interactive evolution and potentially useful tests of theory.

Abstract. New and complete UBV light curves and times of minimum are presented for the Algol-type eclipsing binary V477 Cygni (Sp. A3 V+F5 V, m v = 8.5, P = 2.347 days). The binary orbit of the system is highly eccentric and the system shows an apsidal motion. Using the Wilson-Devinney method, two photometric models, without (MODEL A) and with (MODEL B) third-body light contribution to the total light of the system, are obtained. Period analysis also gives some slender evidence for the unseen third-body in the system with the orbital period of about 157 years. In the MODEL A approximation the apsidal motion period is obtained to be 371 years while it is about 434 years in the MODEL B approximation. The photometric mass ratio (q ∼ 0.75) is in good agreement with the spectroscopic value given by Popper (1968). The masses we obtained are 1.80 ± 0.10 M and 1.35 ± 0.08 M and the radii are 1.60 ± 0.03 R and 1.42 ± 0.03 R for the primary and secondary components, respectively. Absolute dimensions have been compared with the models using a moderate amount of convective overshooting and mass loss given by Claret & Giménez (1991). In the log M -log R diagram both components are located above but close to the ZAMS. It is possible to say from the log T e -log L diagram that the secondary component is just coming to the main sequence while the primary is slightly evolved from the ZAMS. The theoretical evolutionary models give an age of 6.4 × 10 8 yrs for the system.

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