Radial velocity curve for HD 332231 b. Radial velocities from HARPS-N, Levy, HIRES, and SONG shown with blue, orange, green, and red error bars, respectively. The grey line is the best-fitting model of the orbit modulated by the RM effect, which is obscured by the HARPS-N data. The coloured error bars are the nominal errors, and the black error bar is the nominal error with the jitter term added in quadrature.