Narrow-band light curves of UX UMa, centred at the H-beta line (a) and at 4,800 Å in the nearby continuum (b), in mJy. The continous lines represent the fits to the light curves. The corresponding disk images are presented as c and d. The Roche lobe, with the L1 point at the centre of the lower boundary, is plotted for reference. [ TIFF ]