Gravitational binary-lens events with prominent effects of lens orbital motion

Journal Article · Sun Dec 01 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/2/134· OSTI ID:22341926

Park, H.; Han, C.; Choi, J. -Y. ^[1]; Udalski, A.; Szymański, M. K.; Kubiak, M.; Soszyński, I.; Pietrzyński, G.; Poleski, R.; Ulaczyk, K.; Pietrukowicz, P.; Kozłowski, S.; Skowron, J.; Wyrzykowski, Ł. ^[2]; Gould, A.; Gaudi, B. S. ^[3]; Beaulieu, J. -P. ^[4]; Tsapras, Y. ^[5]; Depoy, D. L. ^[6]; Dong, Subo ^[7] ; others, and

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1. Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of)
2. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
3. Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
4. Institut d'Astrophysique de Paris, UMR 7095 CNRS-Université Pierre and Marie Curie, 98bis Bd Arago, F-75014 Paris (France)
5. Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States)
6. Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)
7. Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

Gravitational microlensing events produced by lenses composed of binary masses are important because they provide a major channel for determining physical parameters of lenses. In this work, we analyze the light curves of two binary-lens events, OGLE-2006-BLG-277 and OGLE-2012-BLG-0031, for which the light curves exhibit strong deviations from standard models. From modeling considering various second-order effects, we find that the deviations are mostly explained by the effect of the lens orbital motion. We also find that lens parallax effects can mimic orbital effects to some extent. This implies that modeling light curves of binary-lens events not considering orbital effects can result in lens parallaxes that are substantially different from actual values and thus wrong determinations of physical lens parameters. This demonstrates the importance of routine consideration of orbital effects in interpreting light curves of binary-lens events. It is found that the lens of OGLE-2006-BLG-277 is a binary composed of a low-mass star and a brown dwarf companion.

• OSTI ID: 22341926
• Journal Information: Astrophysical Journal, Vol. 778, Issue 2; 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
DATA
GRAVITATIONAL LENSES
MASS
PLANETS
SATELLITES
SIMULATION
STANDARD MODEL
STARS
VISIBLE RADIATION