Rossiter–McLaughlin effect displayed in four ways, for the illustrative case of WASP-50. Top right: schematic of the planet transiting the stellar disk. The wedge represents the best-fit λ and its uncertainty. The color scheme is based on the star’s rotational Doppler shift; the same color scheme is used in the top left and lower left panels to convey the location of the planet on the star. Top left: spectral lines. The thick black curve is the average out-of-transit cross-correlation function (CCF) and the superimposed white curve is a CCF observed near mid-transit. Middle left: spectral line distortions. Shown are the results of subtracting five of the in-transit CCFs from the mean out-of-transit CCF. Solid curves show the data. Dashed curves are the best-fit Lorentzian profiles, with vertical lines marking their centers. The color coding is done according to the apparent velocity anomaly going from redshifted (in red) to blueshifted (in blue). Bottom left: Doppler shadow. Each row shows the spectral line distortion at a particular time. The white contours are amplitude levels of the distortion. Each small circle marks the best-fit subplanetary velocity (the Doppler shift of the portion of the star directly behind the planet’s center), with colors that convey the corresponding anomalous radial velocity shown in the lower right panel. Dark vertical lines mark the measured v sin i_★, and the diagonal white line is the best-fit trajectory. Bottom right: anomalous radial velocities. The dark shaded area is the range of times when the planet’s silhouette is completely contained within the stellar disk.