Abstract
The purpose of this thesis is to search for p-mode oscillations in the GW Vir white dwarf RX J2117.1+3412. This target was observed at time resolution 50 ms using a high-speed photometry system MIOSOTYS at a 1.93 m telescope for four nights in 2010. A high-speed photometry system is required since the p-mode oscillations in white dwarfs are at the time scale of seconds or less. We analysed the photometric data by Fast Fourier Transform and the Lomb-Scargle Periodogram. P-mode oscillations were not detected in our analysis. We have also conducted a series of simulations to estimate the upper limits to the p-modes amplitude. We conclude that an upper limit to the relative amplitude can be set at 2.5×10^-3 in the frequency range 1 to 10 Hz with 3σ confidence level.