@article{3068810,
    title = "Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye",
    author = "Wyrzykowski, Ł. and Mróz, P. and Rybicki, K.A. and Gromadzki, M. and Kołaczkowski, Z. and Zieliński, M. and Zieliński, P. and Britavskiy, N. and Gomboc, A. and Sokolovsky, K. and Hodgkin, S.T. and Abe, L. and Aldi, G.F. and Almannaei, A. and Altavilla, G. and Al Qasim, A. and Anupama, G.C. and Awiphan, S. and Bachelet, E. and Baklş, V. and Baker, S. and Bartlett, S. and Bendjoya, P. and Benson, K. and Bikmaev, I.F. and Birenbaum, G. and Blagorodnova, N. and Blanco-Cuaresma, S. and Boeva, S. and Bonanos, A.Z. and Bozza, V. and Bramich, D.M. and Bruni, I. and Burenin, R.A. and Burgaz, U. and Butterley, T. and Caines, H.E. and Caton, D.B. and Calchi Novati, S. and Carrasco, J.M. and Cassan, A. and Epas, V. and Cropper, M. and Chruślińska, M. and Clementini, G. and Clerici, A. and Conti, D. and Conti, M. and Cross, S. and Cusano, F. and Damljanovic, G. and Dapergolas, A. and D'Ago, G. and De Bruijne, J.H.J. and Dennefeld, M. and Dhillon, V.S. and Dominik, M. and Dziedzic, J. and Erece, O. and Eselevich, M.V. and Esenoglu, H. and Eyer, L. and Figuera Jaimes, R. and Fossey, S.J. and Galeev, A.I. and Grebenev, S.A. and Gupta, A.C. and Gutaev, A.G. and Hallakoun, N. and Hamanowicz, A. and Han, C. and Handzlik, B. and Haislip, J.B. and Hanlon, L. and Hardy, L.K. and Harrison, D.L. and Van Heerden, H.J. and Hoette, V.L. and Horne, K. and Hudec, R. and Hundertmark, M. and Ihanec, N. and Irtuganov, E.N. and Itoh, R. and Iwanek, P. and Jovanovic, M.D. and Janulis, R. and Jelínek, M. and Jensen, E. and Kaczmarek, Z. and Katz, D. and Khamitov, I.M. and Kilic, Y. and Klencki, J. and Kolb, U. and Kopacki, G. and Kouprianov, V.V. and Kruszyńska, K. and Kurowski, S. and Latev, G. and Lee, C.-H. and Leonini, S. and Leto, G. and Lewis, F. and Li, Z. and Liakos, A. and Littlefair, S.P. and Lu, J. and Manser, C.J. and Mao, S. and Maoz, D. and Martin-Carrillo, A. and Marais, J.P. and Maskoliūnas, M. and Maund, J.R. and Meintjes, P.J. and Melnikov, S.S. and Ment, K. and Mikołajczyk, P. and Morrell, M. and Mowlavi, N. and Mo Dzierski, D. and Murphy, D. and Nazarov, S. and Netzel, H. and Nesci, R. and Ngeow, C.-C. and Norton, A.J. and Ofek, E.O. and Pakštienė, E. and Palaversa, L. and Pandey, A. and Paraskeva, E. and Pawlak, M. and Penny, M.T. and Penprase, B.E. and Piascik, A. and Prieto, J.L. and Qvam, J.K.T. and Ranc, C. and Rebassa-Mansergas, A. and Reichart, D.E. and Reig, P. and Rhodes, L. and Rivet, J.-P. and Rixon, G. and Roberts, D. and Rosi, P. and Russell, D.M. and Zanmar Sanchez, R. and Scarpetta, G. and Seabroke, G. and Shappee, B.J. and Schmidt, R. and Shvartzvald, Y. and Sitek, M. and Skowron, J. and Niegowska, M. and Snodgrass, C. and Soares, P.S. and Van Soelen, B. and Spetsieri, Z.T. and Stankevičiūtė, A. and Steele, I.A. and Street, R.A. and Strobl, J. and Strubble, E. and Szegedi, H. and Tinjaca Ramirez, L.M. and Tomasella, L. and Tsapras, Y. and Vernet, D. and Villanueva, S. and Vince, O. and Wambsganss, J. and Van Der Westhuizen, I.P. and Wiersema, K. and Wium, D. and Wilson, R.W. and Yoldas, A. and Zhuchkov, R.Y. and Zhukov, D.G. and Zdanavičius, J. and Zoła, S. and Zubareva, A.",
    journal = "Chinese Astronomy and Astrophysics",
    year = "2020",
    volume = "633",
    publisher = "EDP Sciences",
    issn = "0275-1062",
    doi = "10.1051/0004-6361/201935097",
    keywords = "Earth (planet);  Geometrical optics;  Photometry;  Systems (metallurgical);  Telescopes, Coordinated observations;  Event evolutions;  Galactic bulge;  Main sequence stars;  Orbital parameters;  Orbital periods;  Photometric data;  Radial velocity curves, Orbits",
    abstract = "Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I? =? 12 mag, and it was covered in great detail with almost 25 000 data points gathered by a network of telescopes. We present the photometric and spectroscopic follow-up covering 500 days of the event evolution. We employed a full Keplerian binary orbit microlensing model combined with the motion of Earth and Gaia around the Sun to reproduce the complex light curve. The photometric data allowed us to solve the microlensing event entirely and to derive the complete and unique set of orbital parameters of the binary lensing system. We also report on the detection of the first-ever microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and we found that the system is composed of two main-sequence stars with masses 0.57 ± 0.05 M? and 0.36 ± 0.03 M? at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30. We also predict the astrometric microlensing signal for this binary lens as it will be seen by Gaia as well as the radial velocity curve for the binary system. Events such as Gaia16aye indicate the potential for the microlensing method of probing the mass function of dark objects, including black holes, in directions other than that of the Galactic bulge. This case also emphasises the importance of long-term time-domain coordinated observations that can be made with a network of heterogeneous telescopes. © ESO 2020."
}