Radial velocity of Achernar A from the cross correlation technique. Top left: a CCF profile of Achernar A, built from a CHIRON stacked spectrum cross-correlated with a binary template including the five reddest He I lines (line set 3), and fit with a generalized normal distribution (GND, see text). Other panels: resulting RV time series from the same five-line binary template (top right), from a binary template including the six less asymmetric He I lines (bottom left), and from a binary template including only the two He I lines common to both previous templates (bottom right), respectively.