Close-up view of the radial-velocity measurements of HAT-P-8, HAT-P-9, HAT-P-16, and HAT-P-23 obtained with SOPHIE during transit nights. The best-fit Rossiter-McLaughlin models are superimposed as a red dashed line. FIES data of HAT-P-8 are included as green circles (Simpson et al. 2010). Data for two separate observing nights are shown with different symbols for HAT-P-9 (filled circles: 28 December 2010, open circles: 1 January 2011).