Photometry of eclipsing dwarf-nova EX Draconis was performed at the observatory of Astronomical Institute of the Academy of Sciences of the Czech Republic in Ondřejov and at the Astronomical Observatory on Kolonické sedlo during 63 nights. I calculated times of minimum light by two methods - the mirror method and the derivative method. The mirror method is more precise for these measurements with longer exposure time and smaller coverage of the light curve of eclipse. 53 new times of minima calculated by the mirror method and times of minima obtained from the older articles about EX Dra were included in the O-C diagram and fitted by the sine function and theoretical curve of LITE caused by an unseen third body. Period of cyclic changes for the sine function is 25 years, instead of 4 or 5 years period given in older papers.Period of the third body orbit is aproximately 17 years and its minimum mass is 53.5 Jupiter's mass. The sum of squared deviations is 5 times smaller for the LITE, which means that the LITE ilustrates the O-C diagram better. I determined the average outburst period for three observational seasons and I drew the phase curve of outburst. Finally, I calculated the short period of the light changes outside eclipse.

We present the modes identified for frequencies found in spectroscopic observations of the Doradus stars HD 189631, QW Puppis, and IR Draconis. A cross-correlation tech- nique was used to create mean line profiles for HD 189631. Four frequencies and modes were identified for this star: 1.6774±0.0002 d⁻¹, 1.4174±0.0002 d⁻¹, 0.0714±0.0002 d⁻¹, and 1.8228 ± 0.0002 d⁻¹ which were identified with the modes (l,m) = (1, +1), (1, +1), (2,−2), and (1, +1) respectively. A least-squares deconvolution method was implemented for line profile generation in the study of QW Puppis and IR Draconis. Three frequen- cies were identified for QW Puppis: 0.055972 ± 0.000004 d⁻¹, 0.064846 ± 0.000004, and 5.219398±0.000002 d⁻¹. These frequencies were identified with the modes (l,m) = (1,−1), (4,−1), (4, +1). Two frequencies were identified in spectra of the rapidly rotating star IR Draconis: 0.00515 ± 0.00003 d⁻¹ and 2.35538 ± 0.00004 d⁻¹; which were identified with (l,m) = (1,−1), and (1, +1) modes respectively. These mode identifications will assist in modelling the structure and interior conditions of these main sequence, non-radially pulsating stars.