Semi-amplitude K of the intrinsically RV-variable stars (blue star markers) and the stars with as yet unknown origin of their RV variations (cyan hexagons) plotted against the luminosity. The literature stars are plotted with reduced sizes. We further plot the estimated p-mode jitter following the scaling relations by Kjeldsen & Bedding (1995), labeled K&B95, for three different stellar masses. We observe that many of the stars follow a roughly linear relation between the amplitude of their RV variation and the luminosity. Two outliers at large L but small K are noted. These are HIP 46390 and HIP 38253. We exclude the very luminous star NGC 2345 No. 50 from the plot for visual clarity.