Optima ile hizli fotometri ve polarimetri

Cataclysmic variables are interacting close binaries which constitute a general class of binary star systems. These systems radiate in the radio through gamma-ray bandpasses, hence several hundreds of those close to our Sun have been studied extensivelywith ground-based and space-based telescopes. The cataclysmic variable systems contain an accreting white dwarf and a normal star companion. The entire binary system usually has the size of the Sun with an orbital period in the range of 1-10 hour. In this work, general properties of cataclysmic variables were reviewed, and fast-photometric and X-ray observations of two magnetic cataclysmic variables, HU Aqr (polar) and V2069 Cyg (intermediate polar), were presented. Additionaly, in order to calibrate the polarimeter mode of OPTIMA (OPtical TIming Analyzer) some polarization measurements and polarimetric observations of some standart stars were obtained. The fast photometric and polarimetric observations were performed withOPTIMA instrument at the 1.3 m telescope at Skinakas Observatory (Crete). The Xray observations were performed with the XMM-Newton and Swift/XRT telescopes. The timing analyse of the optical/X-ray light curves of V2069 Cyg showed doublepeakedemission profile at the white dwarf spin period. Here, we discussed the probable mechanism which causes double-peaked profile. Furthermore, we presented the X-ray spectra obtained from the XMM-Newton EPIC instruments. Additionally, weinvestigated the long term orbital period change of the eclipsing binary system HU Aqr. We created O?C (observed minus calculated) light curves of the system including recent observations together with the existing data in the literature. We discussed probable mechanisms which cause the orbital period change of binary systems.