VRI photometry of MOA 2009-BLG-319

The ~10yr baseline between the event and the Keck observations allows the planetary host star to be detected at a separation of 66.5{+/-}1.7mas from the source star, consistent with the light-curve model prediction. The combination of the host star brightness and light-curve parameters yields host star and planet masses of M_host_=0.524{+/-}0.048M{sun} and m_p_=67.3{+/-}6.2M{Earth} at a distance of DL=7.1{+/-}0.7kpc.

The star-planet projected separation is 2.03{+/-}0.21au. The planet-to-star mass ratio of this system, q=(3.857{+/-}0.029)x10^-4^, places it in the predicted "planet desert" at 10^-4^<q<4x10^-4^ according to the runaway gas accretion scenario of the core accretion theory. Seven of the 30 planets in the Suzuki et al. sample fall in this mass ratio range, and this is the third with a measured host mass.