标题： KMT-2018-BLG-1743：发生在两颗恒星上的行星微透镜事件 显示英文标题

标题： KMT-2018-BLG-1743: Planetary Microlensing Event Occurring on Two Source Stars

摘要： 我们分析了微透镜事件 KMT-2018-BLG-1743。该事件的光变曲线，峰值放大倍数为$A_{\rm peak}\sim 800$，表现出两个异常特征，一个在峰值附近，另一个在光变曲线下降侧。用双透镜和单源（2L1S）解释无法描述这些异常。通过进行额外建模，相对于2L1S解释，包括额外透镜（3L1S）或额外源（2L2S），我们发现2L2S解释与行星透镜系统和双源最好地解释了观测到的光变曲线，分别具有$\Delta\chi^2\sim 188$和$\sim 91$。假设这些$\Delta\chi^2$值足以区分模型，该事件是第四个2L2S事件和第二个2L2S行星事件。2L2S解释存在一种退化，导致两种解，分别为$s>1.0$（宽解）和$s<1.0$（密解）。 透镜组件的质量和透镜的距离分别为宽解和紧解中的$(M_{\rm host}/M_\odot, M_{\rm planet}/M_{\rm J}, D_{\rm L}/{\rm kpc}) \sim (0.19^{+0.27}_{-0.111}, 0.25^{+0.34}_{-0.14}, 6.48^{+0.94}_{-1.03})$和$\sim (0.42^{+0.34}_{-0.25}, 1.61^{+1.30}_{-0.97}, 6.04^{+0.93}_{-1.27})$。 光源是由一个早G型矮星和一个中M型矮星组成的双星。 从两个简并解中预期的相对透镜-源自行运动值分别为$\mu_{\rm wide}\sim 2.3 $毫角秒 年$^{-1}$和$\mu_{\rm close} \sim 4.1 $毫角秒 年$^{-1}$，两者有显著不同，因此可以通过未来高分辨率成像观测分辨透镜和光源来打破简并性。 显示英文摘要

摘要： We present the analysis of the microlensing event KMT-2018-BLG-1743. The light curve of the event, with a peak magnification $A_{\rm peak}\sim 800$, exhibits two anomaly features, one around the peak and the other on the falling side of the light curve. An interpretation with a binary lens and a single source (2L1S) cannot describe the anomalies. By conducting additional modeling that includes an extra lens (3L1S) or an extra source (2L2S) relative to a 2L1S interpretation, we find that 2L2S interpretations with a planetary lens system and a binary source best explain the observed light curve with $\Delta\chi^2\sim 188$ and $\sim 91$ over the 2L1S and 3L1S solutions, respectively. Assuming that these $\Delta\chi^2$ values are adequate for distinguishing the models, the event is the fourth 2L2S event and the second 2L2S planetary event. The 2L2S interpretations are subject to a degeneracy, resulting in two solutions with $s>1.0$ (wide solution) and $s<1.0$ (close solution). The masses of the lens components and the distance to the lens are $(M_{\rm host}/M_\odot, M_{\rm planet}/M_{\rm J}, D_{\rm L}/{\rm kpc}) \sim (0.19^{+0.27}_{-0.111}, 0.25^{+0.34}_{-0.14}, 6.48^{+0.94}_{-1.03})$ and $\sim (0.42^{+0.34}_{-0.25}, 1.61^{+1.30}_{-0.97}, 6.04^{+0.93}_{-1.27})$ according to the wide and close solutions, respectively. The source is a binary composed of an early G dwarf and a mid M dwarf. The values of the relative lens-source proper motion expected from the two degenerate solutions, $\mu_{\rm wide}\sim 2.3 $mas yr$^{-1}$ and $\mu_{\rm close} \sim 4.1 $mas yr$^{-1}$, are substantially different, and thus the degeneracy can be broken by resolving the lens and source from future high-resolution imaging observations.