VRI light curve of MOA 2020-BLG-135

With a derived mass ratio of q=1.52_-0.31_^+0.39^x10^-4^ and separation s~1, the planet lies exactly at the break and likely peak of the exoplanet mass-ratio function derived by the Microlensing Observations in Astrophysics (MOA) Collaboration. We estimate the properties of the lens system based on a Galactic model and considering two different Bayesian priors: one assuming that all stars have an equal planet-hosting probability and the other that planets are more likely to orbit more-massive stars.

With a uniform host mass prior, we predict that the lens system is likely to be a planet of mass m_p_=11.3_-6.9_^+19.2^M{Earth} and a host star of mass M_*_=0.23_-0.14_^+0.39^M{sun}, located at a distance D_L_=7.9_-1.0_^+1.0^kpc. With a prior that holds that planet occurrence scales in proportion to the host-star mass, the estimated lens system properties are m_p_=25_-15_^+22^M{Earth}, M_*_=0.53_-0.32_^+0.42^M{sun}, and D_L_=8.3_-1.0_^+0.9^kpc.