Photoelectric observations of the WR binary CQ Cephei (WN6S09) are presented. The depths of the eclipses in the light curves are best represented by an inclination of the orbit z = (68O.8 f 0.6) and the width of the very asymmetric eclipse curves can be represented by only an overcontact configuration (01 = Rz = 3.65 f 0.05, and f = 27% Here, we report the new photometric data, present the results of a new analysis of the photometric data, and discuss the nature of the system revealed by the new analysis. 2. ObservationsPhotoelectric UBV observations were obtained in 1995 and 1996 in 7 nights with the 30 cm Maksutov telescope, and in 16 nights with the 30 cm Cassegrain telescope, both at the Ankara University Observatory. The photometers used are the standard SSP-5 in the Maksutov, and SSP-5A in the Cassegrain telescopes. BD +56"2815 and BD

UBV observations of the massive binary system TT Aur were carried out mainly at theTurkish National Observatory (TUG). These observations, together with IUE spectra and times of eclipse minima collected from the literature, were used to study the system parameters.Simultaneous solution of the light curves by the Wilson-Devinney code allows a semi-detached configuration with a slightly larger Roche-lobe filling secondary. This picture is supported by other evidence. The shoulders of the primary minimum suggest some excess absorption, in keeping with circumstellar material in the form of a disk-like structure around the primary component. The deeper primary minimum in the U filter may indicate a hotter region on the secondary-facing hemisphere of the primary.The period variation of the system can also be related to the possible existence of a third component in a circular orbit around the system.An alternative detached representation is also considered using optimal curve-fitting techniques. We appeal for further observations to help resolve some outstanding issues in this interesting massive binary.

The UBVR photoelectric observations of the variable star EM Cep were made at the Abastumani Astrophysical Observatory, Georgia. On 15-16 November 1991 an unusual flare of this star was revealed. On 17-18 July 2003, flare activity of EM Cep was detected by Turkish astronomers. A suggestion as to the λ Eri-type variability of the star is made.

No abstract

No abstract

No abstract

No abstract

No abstract