OGLE-2005-BLG-018: CHARACTERIZATION OF FULL PHYSICAL AND ORBITAL PARAMETERS OF A GRAVITATIONAL BINARY LENS

Journal Article · Sun Jul 10 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/735/2/85· OSTI ID:21578422

Shin, I -G; Han, C ^[1]; Udalski, A; Kubiak, M; Szymanski, M K; Pietrzynki, G; Soszynski, I; Ulaczyk, K; Wyrzykowski, L ^[2]; Gould, A; Gaudi, B S; Pogge, R W ^[3]; Dominik, M ^[4]; Fouque, P ^[5]; DePoy, D L ^[6]; Dong, S ^[7]; Lee, C -U; Park, B -G ^[8]; Albrow, M D ^[9]; Allan, A ^[10]

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1. Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)
2. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
3. Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States)
4. SUPA School of Physics and Astronomy, University of St. Andrews, KY16 9SS (United Kingdom)
5. IRAP, Universite de Toulouse, CNRS, 14 av. E. Belin, 31400 Toulouse (France)
6. Department of Physics, Texas A and M University, College Station, TX 77843-4242 (United States)
7. Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)
8. Korea Astronomy and Space Science Institute, 61-1 Hwaam-Dong, Yuseong-Gu, Daejeon 305-348 (Korea, Republic of)
9. Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020 (New Zealand)
10. School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)

We present the result of the analysis of the gravitational binary-lensing event OGLE-2005-BLG-018. The light curve of the event is characterized by two adjacent strong features and a single weak feature separated from the strong features. The light curve exhibits noticeable deviations from the best-fit model based on standard binary parameters. To explain the deviation, we test models including various higher-order effects of the motions of the observer, source, and lens. From this, we find that it is necessary to account for the orbital motion of the lens in describing the light curve. From modeling the light curve considering the parallax effect and Keplerian orbital motion, we are able to not only measure the physical parameters but also to find a complete orbital solution of the lens system. It is found that the event was produced by a binary lens located in the Galactic bulge with a distance of 6.7 {+-} 0.3 kpc from the Earth. The individual lens components with masses 0.9 {+-} 0.3 M{sub sun} and 0.5 {+-} 0.1 M{sub sun} are separated with a semi-major axis of a = 2.5 {+-} 1.0 AU and orbiting each other with a period P = 3.1 {+-} 1.3 yr. This event demonstrates that it is possible to extract detailed information about binary lens systems from well-resolved lensing light curves.

• OSTI ID: 21578422
• Journal Information: Astrophysical Journal, Vol. 735, Issue 2; Other Information: DOI: 10.1088/0004-637X/735/2/85; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DIAGRAMS
GRAVITATIONAL LENSES
SIMULATION
VISIBLE RADIATION
ELECTROMAGNETIC RADIATION
INFORMATION
LENSES
RADIATIONS