(a) The colored line is an example of the blue CCD spectrum of WASP-33 after standard reduction. Different colors mean different orders. The black line is the Coelho model spectrum. (b) The barycentric-corrected RV of WASP-33 during the observation (red star), as a result of combining the RV of each order that has the highest cross-correlation signal. The blue line is the weighted median combination of all frames that was taken as the RV of WASP-33. The error bar is the 1σ scatter across the observation time.