Abstract. New extensive multicolour photoelectric photometry, performed since 1994, is presented. 17 moreor-less complete light curves were obtained and analyzed. The Wilson-Devinney code applied to the BVRI light curves without the maculation effect together with published spectroscopic mass ratio and semi-major axis yielded new absolute parameters of the eclipsing pair: m1 = 1.10 M , m2 = 0.66 M , R1 = 1.16 R , R2 = 0.63 R , a = 3.107 R and the orbital inclination i = 80.9• . The observed orbital period changes are conclusively explained by the mutual action of the third body in the system (P3 = 30 years) and the maculation effects. Simultaneous analysis of the period changes and the visual brightness excludes the possibility of their explanation by Applegate's mechanism. The differences in the maxima heights caused by the maculation exhibit variations with the period of 709± 10 days. The distance to the system d = 86± 5 pc determined from the absolute dimensions and luminosities of the components is larger than the Hipparcos astrometric value d = 66 ± 6 pc.

We determined new linear ephemerides of transiting exoplanets using long-cadence de-trended data from quarters Q1 to Q17 of Kepler mission. We analysed TTV diagrams of 2098 extrasolar planets. The TTVs of 121 objects were excluded (because of insufficient data-points, influence of stellar activity, etc). Finally, new linear ephemerides of 1977 exoplanets from Kepler archive are presented. The significant linear trend was observed on TTV diagrams of approximately 35% of studied exoplanets. Knowing correct linear ephemeris is principal for successful follow-up observations of transits. Residual TTV diagrams of 64 analysed exoplanets shows periodic variation, 43 of these TTV planets were not reported yet.

Tightest known quadruple system VW LMi consists of contact eclipsing binary with P12= 0.477 551 d and detached binary with P34= 7.930 63 d revolving in rather tight, 355.0‐d orbit. This paper presents new photometric and spectroscopic observations yielding 69 times of minima and 36 disentangled radial velocities for the component stars. All available radial velocities and minima times are combined to better characterize the orbits and to derive absolute parameters of components. The total mass of the quadruple system was estimated at 4.56 M⊙. The detached, non‐eclipsing binary with orbital period P= 7.93 d is found to show apsidal motion with U≈ 80 yr. Precession period in this binary, caused by the gravitational perturbation of the contact binary, is estimated to be about 120 yr. The wide mutual orbit and orbit of the non‐eclipsing pair are found to be close to coplanarity, preventing any changes of the inclination angle of the non‐eclipsing orbit and excluding occurrence of the second system of eclipses in future. Possibilities of astrometric solution and direct resolving of the wide, mutual orbit are discussed. Nearby star, HD 95606, was found to form loose binary with quadruple system VW LMi.