E. Bachelet, M. Hundertmark, V. Bozza, J. -P. Beaulieu, A. Udalski

We report the discovery and characterization of a planetary system in the microlensing event OGLE-2013-BLG-1125/MOA-2013-BLG-584. We analyze photometric data from OGLE and MOA surveys, as well as LCO, $μ$FUN, and Mindstep follow-up telescopes to model the microlensing light curve. We also used data from the Keck II telescope collected in 2018 to obtain additional constraints on the lensing system. We found a Saturn-mass planet of mass $M_{\rm p}=105\pm13 \ M_\oplus$ orbiting a low-mass host star $M_{\rm L}=0.139\pm0.011 \ M_\odot$ at $1.00\pm0.08$ kpc from Earth. This discovery adds to the small sample of giant planets orbiting low-mass stars and provides constraints on planet formation theories.