Relation between v sin(i), age, and T_eff for stars observed in the RVSPY high-cadence programme. T_eff is coded in colour. Stars marked as triangles do not have a significant IR excess (see Sect. 3.1). Coloured dashed lines show separate linear fits to the relation between log(v sin(i)) and log(age) for stars with T_eff < 6000 K (dark red) and stars with T_eff > 6500 K (dark yellow). The horizontal dashed-dotted line marks the lower sensitivity limit of our v sin(i) measurements.