Han CUdalski ABond IALee C-UGould AAlbrow MDChung S-JHwang K-HJung YKRyu Y-HShvartzvald YShin I-GYee JCYang HZang WCha S-MKim DKim D-JKim S-LLee D-JLee YPark B-GPogge RWMróz PSzymanski MKSkowron JPoleski RSoszynski IPietrukowicz PKozłowski SRybicki KAIwanek PUlaczyk KWrona MGromadzki MMróz MJAbe FBarry RBennett DPBhattacharya AFujii HFukui AHamada RHirao YIshitani Silva SItow YKirikawa RKoshimoto NMatsubara YMiyazaki SMuraki YOlmschenk GRanc CRattenbury NJSatoh YSumi TSuzuki DTomoyoshi MTristram PJVandorou AYama HYamashita K2025-01-142025-01-142024-12Han C, Udalski A, Bond IA, Lee CU, Gould A, Albrow MD, Chung SJ, Hwang KH, Jung YK, Ryu YH, Shvartzvald Y, Shin IG, Yee JC, Yang H, Zang W, Cha SM, Kim D, Kim DJ, Kim SL, Lee DJ, Lee Y, Park BG, Pogge RW, Mróz P, Szymanski MK, Skowron J, Poleski R, Soszynski I, Pietrukowicz P, Kozłowski S, Rybicki KA, Iwanek P, Ulaczyk K, Wrona M, Gromadzki M, Mróz MJ, Abe F, Barry R, Bennett DP, Bhattacharya A, Fujii H, Fukui A, Hamada R, Hirao Y, Silva SI, Itow Y, Kirikawa R, Koshimoto N, Matsubara Y, Miyazaki S, Muraki Y, Olmschenk G, Ranc C, Rattenbury NJ, Satoh Y, Sumi T, Suzuki D, Tomoyoshi M, Tristram PJ, Vandorou A, Yama H, Yamashita K. (2024). KMT-2021-BLG-0284, KMT-2022-BLG-2480, and KMT-2024-BLG-0412: Three microlensing events involving two lens masses and two source stars. Astronomy and Astrophysics. 692. December 2024.0004-6361https://mro.massey.ac.nz/handle/10179/72366Aims. We carried out a project involving the systematic analysis of microlensing data from the Korea Microlensing Telescope Network survey. The aim of this project is to identify lensing events with complex anomaly features that are difficult to explain using standard binary-lens or binary-source models. Methods. Our investigation reveals that the light curves of microlensing events KMT-2021-BLG-0284, KMT-2022-BLG-2480, and KMT-2024BLG-0412 display highly complex patterns with three or more anomaly features. These features cannot be adequately explained by a binary-lens (2L1S) model alone. However, the 2L1S model can effectively describe certain segments of the light curve. By incorporating an additional source into the modeling, we identified a comprehensive model that accounts for all the observed anomaly features. Results. Bayesian analysis, based on constraints provided by lensing observables, indicates that the lenses of KMT-2021-BLG-0284 and KMT-2024-BLG-0412 are binary systems composed of M dwarfs. For KMT-2022-BLG-2480, the primary lens is an early K-type main-sequence star with an M dwarf companion. The lenses of KMT-2021-BLG-0284 and KMT-2024-BLG-0412 are likely located in the bulge, whereas the lens of KMT-2022-BLG-2480 is more likely situated in the disk. In all events, the binary stars of the sources have similar magnitudes due to a detection bias favoring binary source events with a relatively bright secondary source star, which increases detection efficiency.(c) 2024 The Author/sCC BY 4.0https://creativecommons.org/licenses/by/4.0/gravitational lensingmicroJournal article10.1051/0004-6361/2024518061432-0746journal-articleA221