Spectra of RR Lep during eclipses. Downward arrows mark the calculated position of the combined binary components’ lines. (a) The magenta arrows indicate the line centres of the tertiary star’s Na I D doublet. (b) The H_α line is partly infilled broadened to the red; it is marked with a magenta arrow. (c) Secondary eclipse; the Na I D lines of the primary star broadened to the red by the tertiary star (magenta). (d) H_α line broadened to the red. Exposure times were 60 s.