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Published January 1, 2017 | Version Published
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OGLE-2015-BLG-0196: Ground-based Gravitational Microlens Parallax Confirmed by Space-based Observation

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Abstract

In this paper, we present an analysis of the binary gravitational microlensing event OGLE-2015-BLG-0196. The event lasted for almost a year, and the light curve exhibited significant deviations from the lensing model based on the rectilinear lens-source relative motion, enabling us to measure the microlens parallax. The ground-based microlens parallax is confirmed by the data obtained from space-based microlens observations using the Spitzer telescope. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined up to the twofold degeneracy, u_0 < 0 and u_0 > 0, solutions caused by the well-known "ecliptic" degeneracy. It is found that the binary lens is composed of two M dwarf stars with similar masses, M_1 = 0.38 ± 0.04 M_⊙ (0.50 ± 0.05 M_⊙) and M_2 = 0.38 ± 0.04 M_⊙ (0.55 ± 0.06 M_⊙), and the distance to the lens is D_L = 2.77 ± 0.23 kpc (3.30 ± 0.29 kpc). Here the physical parameters outside and inside the parentheses are for the u_0 < 0 and u_0 > 0 solutions, respectively.

Additional Information

© 2017. The American Astronomical Society. Received 2016 September 19; revised 2016 November 7; accepted 2016 November 8; published 2017 January 4. Work by C. Han was supported by the Creative Research Initiative Program (2009-0081561) of National Research Foundation of Korea. The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to A.U. The OGLE Team thanks Profs. M. Kubiak, G. Pietrzyński, and Ł. Wyrzykowski2, former members of the OGLE Team, for their contribution to the collection of the OGLE photometric data over the past years. Work by A.G. was supported by JPL grant 1500811. W.Z. acknowledges the support from NSF grant AST-1516842. Work by J.C.Y. was performed under contract with the California Institute of Technology (Caltech)/Jet Propulsion Laboratory (JPL), funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. Work by C.B.H. and Y.S. was supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, administered by the Universities Space Research Association through a contract with NASA. We acknowledge the high-speed internet service (KREONET) provided by the Korea Institute of Science and Technology Information (KISTI).

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Additional details

Identifiers

Eprint ID
73276
Resolver ID
CaltechAUTHORS:20170105-133319194

Related works

Describes
https://arxiv.org/abs/1611.02765 (URL)

Funding

National Research Foundation of Korea
2009-0081561
National Science Centre (Poland)
MAESTRO 2014/14/A/ST9/00121
JPL
1500811
NSF
AST-1516842
NASA/JPL/Caltech
NASA Sagan Fellowship
NASA Postdoctoral Program

Dates

Created
2017-01-06
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Updated
2021-11-11
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Infrared Processing and Analysis Center (IPAC)