An analysis of binary microlensing event OGLE-2015-BLG-0060

August 2019 • 2019MNRAS.487.4603T

Authors • Tsapras, Y. • Cassan, A. • Ranc, C. • Bachelet, E. • Street, R. • Udalski, A. • Hundertmark, M. • Bozza, V. • Beaulieu, J. P. • Marquette, J. B. • Euteneuer, E. • Bramich, D. M. • Dominik, M. • Figuera Jaimes, R. • Horne, K. • Mao, S. • Menzies, J. • Schmidt, R. • Snodgrass, C. • Steele, I. A. • Wambsganss, J. • Mróz, P. • Szymański, M. K. • Soszyński, I. • Skowron, J. • Pietrukowicz, P. • Kozłowski, S. • Poleski, R. • Ulaczyk, K. • Pawlak, M. • Jørgensen, U. G. • Skottfelt, J. • Popovas, A. • Ciceri, S. • Korhonen, H. • Kuffmeier, M. • Evans, D. F. • Peixinho, N. • Hinse, T. C. • Burgdorf, M. J. • Southworth, J. • Tronsgaard, R. • Kerins, E. • Andersen, M. I. • Rahvar, S. • Wang, Y. • Wertz, O. • Rabus, M. • Calchi Novati, S. • D'Ago, G. • Scarpetta, G. • Mancini, L. • Abe, F. • Asakura, Y. • Bennett, D. P. • Bhattacharya, A. • Donachie, M. • Evans, P. • Fukui, A. • Hirao, Y. • Itow, Y. • Kawasaki, K. • Koshimoto, N. • Li, M. C. A. • Ling, C. H. • Masuda, K. • Matsubara, Y. • Muraki, Y. • Miyazaki, S. • Nagakane, M. • Ohnishi, K. • Rattenbury, N. • Saito, To • Sharan, A. • Shibai, H. • Sullivan, D. J. • Sumi, T. • Suzuki, D. • Tristram, P. J. • Yamada, T. • Yonehara, A. • Robonet Team

Abstract • We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous parts of the light curve was achieved by automated follow-up observations from the robotic telescopes of the Las Cumbres Observatory. We show that, for the first time, all main features of an anomalous microlensing event are well covered by follow-up data, allowing us to estimate the physical parameters of the lens. The strong detection of second-order effects in the event light curve necessitates the inclusion of longer-baseline survey data in order to constrain the parallax vector. We find that the event was most likely caused by a stellar binary-lens with masses M_{\star 1} = 0.87 ± 0.12 M_{⊙} and M_{\star 2} = 0.77 ± 0.11 M_{⊙}. The distance to the lensing system is 6.41 ± 0.14 kpc and the projected separation between the two components is 13.85 ± 0.16 au. Alternative interpretations are also considered.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2019MNRAS.487.4603T
• PDF http://academic.oup.com/mnras/pdf-lookup/doi/10.1093/mnras/stz1404
• PREPRINT http://arxiv.org/abs/1906.02630
• DATA https://irsa.ipac.caltech.edu/bibdata/2019/T/2019MNRAS.487.4603T.html
• ELECTR https://doi.org/10.1093%2Fmnras%2Fstz1404