GJ 3473 (TOI-488) radial velocity curve

Through a joint modelling of follow-up radial velocity observations with CARMENES, IRD, and HARPS together with extensive ground-based photometric follow-up observations with LCOGT, MuSCAT, and MuSCAT2, we determined a precise planetary mass, M_b_=1.86+/-0.30M_{sun}_, and radius, R_b_=1.264+/-0.050R_{sun}_.

Additionally, we report the discovery of a second, temperate, non-transiting planet in the system, GJ 3473 c, which has a minimum mass, M_c_sini=7.41+/-0.91M_{sun}_ and orbital period, P_c_=15.509+/-0.033d. The inner planet of the system, GJ 3473 b, is one of the hottest transiting Earth- sized planets known thus far, accompanied by a dynamical mass measurement, which makes it a particularly attractive target for thermal emission spectroscopy.