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

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...

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 \pm 0.12 \, \mathrmM_ødot $ and $M_\star 2 = 0.77 \pm 0.11 \, \mathrmM_ødot $. 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.

Citation

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., …collaboration, T. M. (2019). An analysis of binary microlensing event OGLE-2015-BLG-0060. Monthly Notices of the Royal Astronomical Society, 487(4), 4603 - 4614. https://doi.org/10.1093/mnras/stz1404

• Journal Article Type: Article
• Acceptance Date: May 16, 2019
• Online Publication Date: May 30, 2019
• Publication Date: Aug 1, 2019
• Publicly Available Date: May 26, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 487
• Issue: 4
• Pages: 4603 - 4614
• DOI: https://doi.org/10.1093/mnras/stz1404
• Keywords: gravitational lensing, micro, methods, observational, techniques, photometric, Galaxy, bulge
• Public URL: https://keele-repository.worktribe.com/output/414059
• Publisher URL: https://doi.org/10.1093/mnras/stz1404