Long-term variations in the EWs (in Å) of the Hα, Hβ, and He iλ 5876 lines in the spectrum of HD 60 848. The lower panel yields the meaning of the different symbols. For each of the three upper panels, the lower horizontal axis yields the date in HJD −2 450 000, whilst the upper horizontal axis yields the epoch expressed as Gregorian calendar years. Typical uncertainties on the EWs are 0.25, 0.25, and 0.20 Å for the Hα, Hβ, and He i λ 5876 lines, respectively. The Coralie spectrum was taken simultaneously with the XMM-Newton observation discussed by Rauw et al. (2013).