Left and middle: RVs (left panel) and EWs (middle panel) of selected lines (He ii 4686 shown as open red circles, O iii 5592 as blue crosses, He i 5876 as cyan asterisks, Na i 5890 as green stars, and Hα as black dots) as a function of time or phase (with 1 /P = 0.01838 d^-1 and T₀ = 2 451 751.707), respectively. Typical errors are <5 km s^-1 for RVs and <10% for EWs (see Table 4). Right: Hα profile observed in 2010 (black, HJD = 2 453 40.538), 2011 (red, HJD = 2 455 642.689), 2013 (green, HJD = 2 456 498.481), and 2015 (blue, HJD = 2 457 116.539).