Interpretation of a short-term anomaly in the gravitational microlensing event MOA-2012-BLG-486

Journal Article · Wed Nov 20 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/1/55· OSTI ID:22342019

Hwang, K. -H.; Choi, J. -Y.; Han, C. ^[1]; Bond, I. A. ^[2]; Sumi, T.; Koshimoto, N. ^[3]; Gaudi, B. S.; Gould, A. ^[4]; Bozza, V. ^[5]; Beaulieu, J. -P. ^[6]; Tsapras, Y. ^[7]; Abe, F.; Fukunaga, D.; Itow, Y. ^[8]; Bennett, D. P. ^[9]; Botzler, C. S.; Freeman, M. ^[10]; Chote, P.; Harris, P. ^[11]; Fukui, A. ^[12] ; others, and

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1. Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)
2. Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland (New Zealand)
3. Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan)
4. Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
5. Dipartimento di Fisica "E. R. Caianiello," Università degli Studi di Salerno, Via S. Allende, I-84081 Baronissi (Italy)
6. UPMC-CNRS, UMR7095, Institut d'Astrophysique de Paris, 98bis boulevard Arago, F-75014 Paris (France)
7. Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States)
8. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan)
9. Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States)
10. Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001 (New Zealand)
11. School of Chemical and Physical Sciences, Victoria University, Wellington (New Zealand)
12. Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan)

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.

• OSTI ID: 22342019
• Journal Information: Astrophysical Journal, Vol. 778, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COLOR
DETECTION
DISTURBANCES
GRAVITATIONAL LENSES
PERTURBATION THEORY
PLANETS
SATELLITES
SIMULATION
VISIBLE RADIATION