Orbital semimajor axis of innermost planet vs. stellar mass for detected planetary systems with three or more planets, with red and green open circles for the planets discovered by transit and radial velocity, respectively, and blue filled circles for 11 confirmed and suspected resonant chain systems (see text for the list). The green dashed lines are the upper and lower estimates of the magnetic truncated radius ﹩{a}_{\mathrm{tr}}﹩ of the protoplanetary disk (Equation (12)), and the black dashed lines are the upper and lower estimates of ﹩4{a}_{\mathrm{tr}}﹩. The solid red line is ﹩{a}_{\mathrm{tr}}﹩ derived by Batygin et al. (2023). The solid blue line is the best-fit straight line to the blue filled circles. Data obtained from NASA Exoplanet Archive.