  In the process of analyzing an observed light curve, one often confronts
various scenarios that can mimic the planetary signals causing difficulties in
the accurate interpretation of the lens system. In this paper, we present the
analysis of the microlensing event OGLE-2016-BLG-0733. The light curve of the
event shows a long-term asymmetric perturbation that would appear to be due to
a planet. From the detailed modeling of the lensing light curve, however, we
find that the perturbation originates from the binarity of the source rather
than the lens. This result demonstrates that binary sources with roughly
equal-luminosity components can mimic long-term perturbations induced by
planets with projected separations near the Einstein ring. The result also
represents the importance of the consideration of various interpretations in
planet-like perturbations and of high-cadence observations for ensuring the
unambiguous detection of the planet.
