MOA-2006-BLG-074 was selected as one of the most promising planetary candidates in a retrospective analysis of the MOA collaboration: its asymmetric high-magnification peak can be perfectly explained by a source passing across a central caustic deformed by a small planet. However, after a detailed analysis of the residuals, we have realized that a single lens and a source orbiting with a faint companion provides a more satisfactory explanation for all the observed deviations from a Paczynski curve and the only physically acceptable interpretation. Indeed the orbital motion of the source is constrained enough to allow a very good characterization of the binary source from the microlensing light curve. The case of MOA-2006-BLG-074 suggests that the so-called xallarap effect must be taken seriously in any attempts to obtain accurate planetary demographics from microlensing surveys.
@article{arxiv.2105.08386,
title = {MOA-2006-BLG-074: recognizing xallarap contaminants in planetary microlensing},
author = {P. Rota and Y. Hirao and V. Bozza and F. Abe and R. Barry and D. P. Bennett and A. Bhattacharya and I. A. Bond and M. Donachie and A. Fukui and H. Fujii and S. Ishitani Silva and Y. Itow and R. Kirikawa and N. Koshimoto and M. C. A. Li and Y. Matsubara and S. Miyazaki and Y. Muraki and G. Olmschenk and C. Ranc and Y. Satoh and T. Sumi and D. Suzuki and P. J. Tristram and A. Yonehara},
journal= {arXiv preprint arXiv:2105.08386},
year = {2021}
}