OGLE-2018-BLG-0584 and KMT-2018-BLG-2119: Two microlensing events with two lens masses and two source stars
Cheongho Han, A. Udalski, Youn Kil Jung, Doeon Kim, Hongjing Yang, Michael D. Albrow, Sun‐Ju Chung, Andrew Gould, Kyu‐Ha Hwang, Hyoun-Woo Kim, Chung‐Uk Lee, Yoon-Hyun Ryu, Yossi Shvartzvald, In-Gu Shin, Jennifer C. Yee, Weicheng Zang, Sang-Mok Cha, Dong-Jin Kim, Seung‐Lee Kim, Dong-Joo Lee, Yongseok Lee, Byeong-Gon Park, Richard W. Pogge, Chun‐Hwey Kim, Woong‐Tae Kim, P. Mróz, M. K. Szymański, J. Skowron, Radosław Poleski, I. Soszyński, P. Pietrukowicz, S. Kozłowski, Krzysztof A. Rybicki, Patryk Iwanek, K. Ulaczyk, Marcin Wrona, M. Gromadzki
Abstract
Aims. We conducted a systematic investigation of the microlensing data collected during the previous observation seasons for the purpose of re-analyzing anomalous lensing events with no suggested plausible models. Methods. We found that two anomalous lensing events, OGLE-2018-BLG-0584 and KMT-2018-BLG-2119, cannot be explained with the usual models based on either a binary-lens single-source (2L1S) or a single-lens binary-source (1L2S) interpretation. We tested the feasibility of explaining the light curves of the events with more sophisticated models by adding either an extra lens (3L1S model) or a source (2L2S model) component to the 2L1S lens system configuration. Results. We find that a 2L2S interpretation explains the light curves of both events well and that for each event there are a pair of solutions resulting from the close and wide degeneracy. For the event OGLE-2018-BLG-0584, the source is a binary composed of two K-type stars and the lens is a binary composed of two M dwarfs. For KMT-2018-BLG-2119, the source is a binary composed of two dwarfs of G and K spectral types and the lens is a binary composed of a low-mass M dwarf and a brown dwarf.