Systematic Reanalysis of KMTNet Microlensing Events. II. Two New Planets in Giant-source Events

• Published in: The Astronomical journal Vol. 169; no. 6; pp. 295 - 313
• Main Authors: Yang, Hongjing, Yee, Jennifer C., Zhang, Jiyuan, Lee, Chung-Uk, Kim, Dong-Jin, Bond, Ian A., Udalski, Andrzej, Hwang, Kyu-Ha, Zang, Weicheng, Qian, Qiyue, Gould, Andrew, Mao, Shude, Albrow, Michael D., Chung, Sun-Ju, Han, Cheongho, Jung, Youn Kil, Ryu, Yoon-Hyun, Shin, In-Gu, Shvartzvald, Yossi, Cha, Sang-Mok, Kim, Hyoun-Woo, Kim, Seung-Lee, Lee, Dong-Joo, Lee, Yongseok, Park, Byeong-Gon, Pogge, Richard W., Abe, Fumio, Bando, Ken, Bennett, David P., Bhattacharya, Aparna, Fukui, Akihiko, Hamada, Ryusei, Hamada, Shunya, Hamasaki, Naoto, Hirao, Yuki, Ishitani Silva, Stela, Itow, Yoshitaka, Koshimoto, Naoki, Matsubara, Yutaka, Miyazaki, Shota, Muraki, Yasushi, Nagai, Tutumi, Nunota, Kansuke, Olmschenk, Greg, Ranc, Clément, Rattenbury, Nicholas J., Satoh, Yuki, Sumi, Takahiro, Suzuki, Daisuke, Terry, Sean K., Tristram, Paul . J., Vandorou, Aikaterini, Yama, Hibiki, Mróz, Przemek, Skowron, Jan, Poleski, Radoslaw, Szymański, Michał K., Soszyński, Igor, Pietrukowicz, Paweł, Kozłowski, Szymon, Ulaczyk, Krzysztof, Rybicki, Krzysztof A., Iwanek, Patryk, Wrona, Marcin
• Format: Journal Article
• Language: English
• Published: The American Astronomical Society 02.06.2025; IOP Publishing
• Subjects: Exoplanets; Gravitational microlensing; Gravitational microlensing exoplanet detection; Light curves; Photometry
• ISSN: 0004-6256; 1538-3881
• DOI: 10.3847/1538-3881/adc73e

In this work, we continue to apply the updated KMTNet tender-love care photometric pipeline to historical microlensing events. We apply the pipeline to a subsample of events from the KMTNet database, which we refer to as the giant source sample. Leveraging the improved photometric data, we conduct a systematic search for anomalies within this sample. The search successfully uncovers four new planet-like anomalies and recovers two previously known planetary signals. After detailed analysis, two of the newly discovered anomalies are confirmed as clear planets: KMT-2019-BLG-0578 and KMT-2021-BLG-0736. Their planet-to-host mass ratios are q  ∼ 4 × 10 −3 and q  ∼ 1 × 10 −4 , respectively. Another event, OGLE-2018-BLG-0421 (KMT-2018-BLG-0831), remains ambiguous. Both a stellar companion and a giant planet in the lens system could potentially explain the observed anomaly. The anomaly signal of the last event, MOA-2022-BLG-038 (KMT-2022-BLG-2342), is attributed to an extra source star. Within this sample, our procedure doubles the number of confirmed planets, demonstrating a significant enhancement in the survey sensitivity.