RX J0859.1+0537. Left, top: SDSS spectra of RX J0859+05 (black curve) and the dM5 star SDSS J101639.10+240814.2 divided by 70 to match the TiO structures in the polar spectrum (red). The difference spectrum (black) shows faint cyclotron lines. Second from top: model cyclotron spectrum (red) fit to the observed difference spectrum (black). Third from top: mean radial-velocity curves of the NEL (green) and the combined BBC and HCV components (yellow) of Hβ, Hγ, and He IIλ4686, measured from the high- and medium-resolution trailed spectra. Bottom: O − C diagram for the times of the primary minimum. Green dots show this work, and open circles show results from Joshi et al. (2020) (see text). Right, top: overall spectral energy distribution, built from nonsimultaneous data (see text). Center panels: V-band light curve of 15 January 1996 and WL light curves of on 4 March 2018, 17 January 2019, and 1 April 2011. The dashed lines schematically separate the emissions of the primary and the secondary pole. Bottom panel: Rosat X-ray light curves taken 1990 with the PSPC and 1996 with the HRI. Phases are from Eq. (6).