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. KoshimotoC. 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 the 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.

Original languageEnglish
Article number55
JournalAstrophysical Journal
Volume778
Issue number1
DOIs
Publication statusPublished - 20 Nov 2013

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Keywords

  • binaries: general
  • gravitational lensing: micro
  • planets and satellites: detection

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Hwang, K. H., Choi, J. Y., Bond, I. A., Sumi, T., Han, C., Gaudi, B. S., Gould, A., Bozza, V., Beaulieu, J. P., Tsapras, Y., Abe, F., Bennett, D. P., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Fukunaga, D., Harris, P., Itow, Y., ... Street, R. A. (2013). Interpretation of a short-term anomaly in the gravitational microlensing event MOA-2012-BLG-486. Astrophysical Journal, 778(1), [55]. https://doi.org/10.1088/0004-637X/778/1/55