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تسجيل مستخدم جديدOGLE-2017-BLG-0039: Microlensing Event with Light from the Lens Identified from Mass Measurement
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We present the analysis of the caustic-crossing binary microlensing event OGLE-2017-BLG-0039. Thanks to the very long duration of the event, with an event time scale $t_{rm E}sim 130$ days, the microlens parallax is precisely measured despite its small value of $piesim 0.06$. The analysis of the well-resolved caustic crossings during both the source stars entrance and exit of the caustic yields the angular Einstein radius $thetaesim 0.6$~mas. The measured $pie$ and $thetae$ indicate that the lens is a binary composed of two stars with masses $sim 1.0~M_odot$ and $sim 0.15~M_odot$, and it is located at a distance of $sim 6$ kpc. From the color and brightness of the lens estimated from the determined lens mass and distance, it is expected that $sim 2/3$ of the $I$-band blended flux comes from the lens. Therefore, the event is a rare case of a bright lens event for which high-resolution follow-up observations can confirm the nature of the lens.
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