SDSS J085414.02+390537.3—A New Asynchronous Polar

Based on data from the ZTF photometric survey, we have revealed asynchrony of the polar SDSS J085414.02+390537.3. A beat period $P_{\textrm{beat}}=24.6± 0.1$ days, during which the system changes its brightness by ${≈}3^m$, is distinguished in the light curves. Power peaks at the white-dwarf rotation period $P_{\textrm{spin}}=113.197± 0.001$ min and orbital period $P_{\textrm{orb}}=113.560± 0.001$ min are revealed in the periodograms, with the corresponding polar asynchrony being $1-P_{\textrm{orb}}/P_{\textrm{spin}}=0.3{%}$. The photometric behavior of the polar points to a change of the main accreting pole during the beat period. Based on the Zeeman splitting of the H$β$ line, we have estimated the mean magnetic field strength of the white dwarf to be $B=28.5± 1.5$ MG. The magnetic field strength near the magnetic pole has been found by modeling the cyclotron spectra to be $B=34± 2$ MG. The Doppler tomograms in the H$β$ line exhibit a distribution of emission sources typical for polars in velocity space with evidence of the transition of the accretion stream from the ballistic trajectory to the magnetic one.