RedDots: Planetary masses in the GJ1061 system from planet-planet interaction

GJ1061 is a very nearby M star hosting three low-mass temperate planets detected from radial velocity variations. The close to 4:2:1 period commensurability of the planets, the available long-term monitoring of the system and new very high-precision radial velocity measurements from ESPRESSO enable the determination of masses from the planet-planet interaction. Using nested sampling, we derived parameter distributions for a co-planar configuration. The three planets (Mb =1.07 +- 0.11M_Earth, Pb =3.2073 +- 0.0003 d, Mc=1.76 +- 0.13M_Earth, Pc=6.6821 +- 0.0008 d, Md =1.55 +- 0.17M_Earth, Pd =13.066 +- 0.002 d) are potentially all rocky with equilibrium temperatures between 360 K and 240 K. This makes the GJ1061 system one of the prime targets for future ground or space based instruments suitable for a direct detection of the planetary atmospheres.