Period–mass diagram indicating magnetic field strength in color and symbol size. Data from this work are shown as circles, and other data are shown as squares. Literature values are from Kochukhov et al. (2020) for young Sun-like stars and for seven additional targets from Shulyak et al. (2017). The solar datum from Trujillo Bueno et al. (2004) is annotated. Gray open circles show stars with known rotation periods as reported by Newton et al. (2017). Dashed lines show values of the Rossby number Ro = 0.1 and 1.0, assuming that bolometric luminosity L_bol ∝ M⁴ and for dwarf stars.