OGLE-2014-BLG-1186: gravitational microlensing providing evidence for a planet orbiting the foreground star or for a close binary source?

M. Dominik, E. Bachelet, V. Bozza +40

(abridged) Using the particularly long gravitational microlensing event OGLE-2014-BLG-1186 with a time-scale $t_{\mathrm{E}}$ ~ 300 d, we present a methodology for identifying the na…