OGLE-2013-BLG-0102La,b: Microlensing binary with components at star/brown-dwarf and brown-dwarf/planet boundaries

Y. K. Jung, A. Udalski, T. Sumi, C. Han, A. Gould, J. Skowron, S. Koz?owski, R. Poleski, ?. Wyrzykowski, M. K. Szyma?ski, G. Pietrzy?ski, I. Soszy?ski, K. Ulaczyk, P. Pietrukowicz, P. Mróz, M. Kubiak, F. Abe, D. P. Bennett, I. A. Bond, C. S. Botzler, M. Freeman, A. Fukui, D. Fukunaga, Y. Itow, N. Koshimoto, P. Larsen, C. H. Ling, K. Masuda, Y. Matsubara, Y. Muraki, S. Namba, K. Ohnishi, L. Philpott, N. J. Rattenbury, To. Saito, D. J. Sullivan, D. Suzuki, P. J. Tristram, N. Tsurumi, K. Wada, N. Yamai, P. C. M. Yock, A. Yonehara, M. Albrow, J.-Y. Choi, D. L. DePoy, B. S. Gaudi, K.-H. Hwang, C.-U. Lee, H. Park, S. Owen, R. W. Pogge, I.-G. Shin, J. C. Yee

(Submitted on 30 Jul 2014)

We present the analysis of the gravitational microlensing event OGLE-2013-BLG-0102. The light curve of the event is characterized by a strong short-term anomaly superposed on a smoothly varying lensing curve with a moderate magnification A max ∼1.5 . It is found that the event was produced by a binary lens with a mass ratio between the components is q=0.13 and the anomaly was caused by the passage of the source trajectory over a caustic located away from the barycenter of the binary. From the analysis of the effects on the light curve due to the finite size of the source and the parallactic motion of the Earth, the physical parameters of the lens system are determined. The measured masses of the lens components are M 1 =0.097±0.011  M ? and M 2 =0.013±0.002  M ? , which correspond to the upper and lower limits of brown dwarfs, respectively. The distance to the lens is 3.02±0.21 kpc and the projected separation between the lens components is 0.80±0.04 AU . These physical parameters lie beyond the detection ranges of other methods, demonstrating that microlensing is a useful method in detecting very low-mass binaries.

Comments:

6 figures, 2 tables, ApJ submitted

Subjects:

Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

Cite as:

arXiv:1407.7926 [astro-ph.SR]

(or arXiv:1407.7926v1 [astro-ph.SR] for this version)

Submission history

From: Cheongho Han 

[v1] Wed, 30 Jul 2014 02:41:24 GMT (447kb)

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