RV_std as a function of the projected rotational velocity. The blue and red lines are two linear regression fits: blue for the lower-envelope RV_std values of the six stars whose RVs are dominated by stellar activity rather than by orbital motion (from left to right: HD 202751, HD 214749, HD 210302, HD 21847, HD 377, and HD 25998), and red for the median RV uncertainties of the same stars. Data points are color-coded by log(R′_HK) to indicate chromospheric activity levels. Since Gaia has known problems with correctly measuring the v sin i of cool dwarfs (T_eff < 4300 K), we removed cool dwarfs from the plot and only make line fits in the v sin i > 7 km s⁻¹ region.