MOA-2006-BLG-074: Recognizing Xallarap Contaminants in Planetary Microlensing

MOA-2006-BLG-074 was selected as one of the most promising planetary candidates in a retrospective analysis MOA collaboration: its asymmetric high-magnification peak can be perfectly explained by source passing across central caustic deformed small planet. However, after detailed residuals, we have realized that single lens and orbiting with faint companion provides more satisfactory explanation for all observed deviations from Paczynski curve only physically acceptable interpretation. Indeed orbital motion is constrained enough to allow very good characterization binary microlensing light curve. The case suggests so-called xallarap effect must taken seriously any attempts obtain accurate demographics surveys.