Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
Creators: name: Skowron, J.
name: Udalski, A.
name: Gould, A.
name: Dong, Subo
name: Monard, L. A. G.
name: Han, C.
name: Nelson, C. R.
name: McCormick, J.
name: Moorhouse, D.
name: Thornley, G.
name: Maury, A.
name: Bramich, D. M.
name: Greenhill, J.
name: Kozlowski, S.
name: Bond, I.
name: Poleski, R.
name: Wyrzykowski, L.
name: Ulaczyk, K.
name: Kubiak, M.
name: Szymanski, M. K.
name: Pietrzynski, G.
name: Soszynski, I.
name: Gaudi, B. S.
name: Yee, J. C.
name: Hung, L. -W.
name: Pogge, R. W.
name: DePoy, D. L.
name: Lee, C. -U.
name: Park, B. -G.
name: Allen, W.
name: Mallia, F.
name: Drummond, J.
name: Bolt, G.
name: Allan, A.
name: Browne, P.
name: Clay, N.
name: Dominik, M.
name: Fraser, S.
name: Horne, K.
name: Kains, N.
name: Mottram, C.
name: Snodgrass, C.
name: Steele, I.
name: Street, R. A.
name: Tsapras, Y.
name: Abe, F.
name: Bennett, D. P.
name: Botzler, C. S.
name: Douchin, D.
name: Freeman, M.
name: Fukui, A.
name: Furusawa, K.
name: Hayashi, F.
name: Hearnshaw, J. B.
name: Hosaka, S.
name: Itow, Y.
name: Kamiya, K.
name: Kilmartin, P. M.
name: Korpela, A.
name: Lin, W.
name: Ling, C. H.
name: Makita, S.
name: Masuda, K.
name: Matsubara, Y.
name: Muraki, Y.
name: Nagayama, T.
name: Miyake, N.
name: Nishimoto, K.
name: Ohnishi, K.
name: Perrott, Y. C.
name: Rattenbury, N.
name: Saito, To.
name: Skuljan, L.
name: Sullivan, D. J.
name: Sumi, T.
name: Suzuki, D.
name: Sweatman, W. L.
name: Tristram, P. J.
name: Wada, K.
name: Yock, P. C. M.
name: Beaulieu, J. -P.
name: Fouque, P.
name: Albrow, M. D.
name: Batista, V.
name: Brillant, S.
name: Caldwell, J. A. R.
name: Cassan, A.
name: Cole, A.
name: Cook, K. H.
name: Coutures, Ch.
name: Dieters, S.
name: Prester, D. Dominis
name: Donatowicz, J.
name: Kane, S. R.
name: Kubas, D.
name: Marquette, J. -B.
name: Martin, R.
name: Menzies, J.
name: Sahu, K. C.
name: Wambsganss, J.
name: Williams, A.
name: Zub, M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present the first example of binary microlensing for which the parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possible by a confluence of two relatively unusual circumstances. First, the binary lens is bright enough (I=15.6) to permit Doppler measurements. Second, we measure not only the usual 7 binary-lens parameters, but also the 'microlens parallax' (which yields the binary mass) and two components of the instantaneous orbital velocity. Thus we measure, effectively, 6 'Kepler+1' parameters (two instantaneous positions, two instantaneous velocities, the binary total mass, and the mass ratio). Since Doppler observations of the brighter binary component determine 5 Kepler parameters (period, velocity amplitude, eccentricity, phase, and position of periapsis), while the same spectroscopy yields the mass of the primary, the combined Doppler + microlensing observations would be overconstrained by 6 + (5 + 1) - (7 + 1) = 4 degrees of freedom. This makes possible an extremely strong test of the microlensing solution. We also introduce a uniform microlensing notation for single and binary lenses, we define conventions, summarize all known microlensing degeneracies and extend a set of parameters to describe full Keplerian motion of the binary lenses.
description: 51 pages, 8 figures, 2 appendices. Submitted to ApJ. Fortran codes for Appendix B are attached to this astro-ph submission and are also available at http://www.astronomy.ohio-state.edu/~jskowron/OGLE-2009-BLG-020/