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We present the results of a temporal and spectral study of the BL Lacertaeobject OJ 287 in optical, UV, and X-ray bands with observations performed bySwift satellite during September 2019--March 2020. In this period, the sourceshowed moderate variability characterized by variability amplitude of$\sim$22--31% in all the wavelengths on a short timescale, except the hardX-ray band which was variable by only $\sim$8%. We observed that the X-ray fluxof the source was significantly dominated by the soft photons below $2$ keV.Soft lags of $\sim$45 days were detected between the optical/UV and soft X-rayemissions, while there is no correlation between the hard X-rays and the lowerenergy bands indicating the presence of two emission components or electronpopulations. Although two components contribute to the X-ray emission, most ofthe 0.3--10 keV spectra were well fitted with an absorbed power-law model whichoutlines the dominance of synchrotron over inverse Compton (IC) mechanism. TheX-ray spectra follow a weak "softer when brighter" trend.

Temporal and Spectral Variability of OJ 287 before the April--June 2020 Outburst