Top: radial velocity curve of V807 Tau (dots – each color corresponds to a rotational cycle) fitted with a sinusoid curve at a fixed period of 4.38 d (dash-dotted curve). Bottom: radial velocity curve folded in phase using a 4.38 day period. The origin of time was set to HJD 2 458 051.69, i.e., 53 periods after the origin of time of the K2 ephemeris (Eq. (1)) in order to set the first ESPaDOnS spectrum at cycle 0 while keeping the fractional rotational phase the same.