* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: OGLE-2009-BLG-020


L

Posts: 131433
Date:
OGLE-2009-BLG-020
Permalink  
 


Title: Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
Authors: J. Skowron, A. Udalski, A. Gould, Subo Dong, L. A. G. Monard, C. Han, C. R. Nelson, J. McCormick, D. Moorhouse, G. Thornley, A. Maury, D. M. Bramich, J. Greenhill, S. Kozlowski, I. Bond (and), R. Poleski, L. Wyrzykowski, K. Ulaczyk, M. Kubiak, M. K. Szymanski, G. Pietrzynski, I. Soszynski (the OGLE Collaboration), B. S. Gaudi, J. C. Yee, L.-W. Hung, R. W. Pogge, D. L. DePoy, C.-U. Lee, B.-G. Park, W. Allen, F. Mallia, J. Drummond, G. Bolt (the muFUN Collaboration), A. Allan, P. Browne, N. Clay, M. Dominik, S. Fraser, K. Horne, N. Kains, C. Mottram, C. Snodgrass, I. Steele, R. A. Street, Y. Tsapras (the RoboNet Collaboration), F. Abe, D. P. Bennett, C. S. Botzler, D. Douchin, M. Freeman, A. Fukui, K. Furusawa, F. Hayashi, J. B. Hearnshaw, S. Hosaka, Y. Itow, K. Kamiya, P. M. Kilmartin, A. Korpela,
W. Lin, C. H. Ling, S. Makita, K. Masuda, Y. Matsubara, Y. Muraki, T. Nagayama, N. Miyake, K. Nishimoto, K. Ohnishi, Y. C. Perrott, N. Rattenbury, To. Saito, L. Skuljan, D. J. Sullivan, T. Sumi, D. Suzuki, W. L. Sweatman, P. J. Tristram, K. Wada, P. C. M. Yock (the MOA Collaboration), J.-P. Beaulieu, P. Fouque, M. D. Albrow, V. Batista, S. Brillant, J. A. R. Caldwell, A. Cassan, A. Cole, K. H. Cook, Ch. Coutures, S. Dieters, D. Dominis Prester, J. Donatowicz, S. R. Kane, D. Kubas, J.-B. Marquette, R. Martin, J. Menzies, K. C. Sahu, J. Wambsganss, A. Williams, M. Zub (the PLANET Collaboration)
et al. (43 additional authors not shown)

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, summarise all known microlensing degeneracies and extend a set of parameters to describe full Keplerian motion of the binary lenses.

Read more (746kb, PDF)

__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard