Planetary system around LTT 1445A unveiled by ESPRESSO: Multiple planets in a triple M-dwarf system

We present radial velocity follow-up obtained with ESPRESSO of the M-type star LTT 1445A (TOI-455), for which a transiting planet b an orbital period 5.4 days was detected by TESS. report discovery second (LTT c) and third non-transiting candidate d) periods 3.12 24.30 days, respectively. The host is main component triple M-dwarf system at distance 6.9 pc. used 84 high-resolution spectra to determine accurate masses 2.3 ± 0.3 M ? 1.0 0.2 planets c minimum mass 2.7 0.7 d. Based on its radius 1.43 0.09 R as derived from TESS observations, has lower density than Earth may therefore hold sizeable atmosphere, makes it prime target James Webb Space Telescope (JWST). Bayesian inference approach nested sampling algorithm set models test robustness retrieved physical values system. There probability 85% that transit grazing, results in large uncertainties 1.60 ?0.34 +0.67 . d orbits inner boundary habitable zone could be JWST.