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arXiv · 1308.5762

Interpretation of a Short-Term Anomaly in the Gravitational Microlensing Event MOA-2012-BLG-486

K. -H. Hwang·J. -Y. Choi·I. A. Bond·T. Sumi·C. Han·B. S. Gaudi·A. Gould·V. Bozza·J. -P. Beaulieu·Y. Tsapras·F. Abe·D. P. Bennett·C. S. Botzler·P. Chote·M. Freeman·A. Fukui·D. Fukunaga·P. Harris·Y. Itow·N. Koshimoto·C. H. Ling·K. Masuda·Y. Matsubara·Y. Muraki·S. Namba·K. Ohnishi·N. J. Rattenbury·To. Saito·D. J. Sullivan·W. L. Sweatman·D. Suzuki·P. J. Tristram·K. Wada·N. Yamai·P. C. M. Yock·A. Yonehara·L. Andrade de Almeida·D. L. DePoy·Subo Dong·F. Jablonski·Y. K. Jung·A. Kavka·C. -U. Lee·H. Park·R. W. Pogge·I. -G. Shin·J. C. Yee·M. D. Albrow·E. Bachelet·V. Batista·S. Brillant·J. A. R. Caldwell·A. Cassan·A. Cole·E. Corrales·Ch. Coutures·S. Dieters·D. Dominis Prester·J. Donatowicz·P. Fouqué·J. Greenhill·U. G. Jørgensen·S. R. Kane·D. Kubas·J. -B. Marquette·R. Martin·P. Meintjes·J. Menzies·K. R. Pollard·A. Williams·D. Wouters·D. M. Bramich·M. Dominik·K. Horne·P. Browne·M. Hundertmark·S. Ipatov·N. Kains·C. Snodgrass·I. A. Steele·R. A. Street
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Abstract

A planetary microlensing signal is generally characterized by a short-term perturbation to the standard single lensing light curve. A subset of binary-source events can produce perturbations that mimic planetary signals, thereby introducing an ambiguity between the planetary and binary-source interpretations. In this paper, we present analysis of the microlensing event MOA-2012-BLG-486, for which the light curve exhibits a short-lived perturbation. Routine modeling not considering data taken in different passbands yields a best-fit planetary model that is slightly preferred over the best-fit binary-source model. However, when allowed for a change in the color during the perturbation, we find that the binary-source model yields a significantly better fit and thus the degeneracy is clearly resolved. This event not only signifies the importance of considering various interpretations of short-term anomalies, but also demonstrates the importance of multi-band data for checking the possibility of false-positive planetary signals.

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K. -H. Hwang, J. -Y. Choi, I. A. Bond, T. Sumi, C. Han, B. S. Gaudi, A. Gould, V. Bozza, J. -P. Beaulieu, Y. Tsapras, F. Abe, D. P. Bennett, C. S. Botzler, P. Chote, M. Freeman, A. Fukui, D. Fukunaga, P. Harris, Y. Itow, N. Koshimoto, C. H. Ling, K. Masuda, Y. Matsubara, Y. Muraki, S. Namba, K. Ohnishi, N. J. Rattenbury, To. Saito, D. J. Sullivan, W. L. Sweatman, D. Suzuki, P. J. Tristram, K. Wada, N. Yamai, P. C. M. Yock, A. Yonehara, L. Andrade de Almeida, D. L. DePoy, Subo Dong, F. Jablonski, Y. K. Jung, A. Kavka, C. -U. Lee, H. Park, R. W. Pogge, I. -G. Shin, J. C. Yee, M. D. Albrow, E. Bachelet, V. Batista, S. Brillant, J. A. R. Caldwell, A. Cassan, A. Cole, E. Corrales, Ch. Coutures, S. Dieters, D. Dominis Prester, J. Donatowicz, P. Fouqué, J. Greenhill, U. G. Jørgensen, S. R. Kane, D. Kubas, J. -B. Marquette, R. Martin, P. Meintjes, J. Menzies, K. R. Pollard, A. Williams, D. Wouters, D. M. Bramich, M. Dominik, K. Horne, P. Browne, M. Hundertmark, S. Ipatov, N. Kains, C. Snodgrass, I. A. Steele, R. A. Street. 2013-08-27. Interpretation of a Short-Term Anomaly in the Gravitational Microlensing Event MOA-2012-BLG-486. https://doi.org/10.1088/0004-637x%2F778%2F1%2F55

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