  We report the discovery of a microlensing planet --- MOA-2016-BLG-227Lb ---
with a large planet/host mass ratio of $q \simeq 9 \times 10^{-3}$. This event
was located near the $K2$ Campaign 9 field that was observed by a large number
of telescopes. As a result, the event was in the microlensing survey area of a
number of these telescopes, and this enabled good coverage of the planetary
light curve signal. High angular resolution adaptive optics images from the
Keck telescope reveal excess flux at the position of the source above the flux
of the source star, as indicated by the light curve model. This excess flux
could be due to the lens star, but it could also be due to a companion to the
source or lens star, or even an unrelated star. We consider all these
possibilities in a Bayesian analysis in the context of a standard Galactic
model. Our analysis indicates that it is unlikely that a large fraction of the
excess flux comes from the lens, unless solar type stars are much more likely
to host planets of this mass ratio than lower mass stars. We recommend that a
method similar to the one developed in this paper be used for other events with
high angular resolution follow-up observations when the follow-up observations
are insufficient to measure the lens-source relative proper motion.
