Map of the CCF_intr during the transit of KELT-10 b. Transit contacts are shown as orange dashed lines. Values are colored as a function of their normalized flux, and plotted as a function of the RV in the star rest frame (in abscissa) and orbital phase (in ordinate). The core of the stellar line from the planet-occulted regions is clearly visible as a bright streak. The magenta solid line shows the stellar surface RV model from the RMR best fit. The small gap in the first part of the transit (at phase ~− 0.005) is due to a missing exposure.