Bibcode
Li, Hongyu; Zhang, Jiyuan; Han, Cheongho; Zang, Weicheng; Jung, Youn Kil; Udalski, Andrzej; Sumi, Takahiro; Yang, Hongjing; Kuang, Renkun; Mao, Shude; Albrow, Michael D.; Chung, Sun-Ju; Gould, Andrew; Ha Hwang, Kyu-; Ryu, Yoon-Hyun; Shin, In-Gu; Shvartzvald, Yossi; Yee, Jennifer C.; Cha, Sang-Mok; Kim, Dong-Jin; Kim, Seung-Lee; Lee, Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge, Richard W.; KMTNet Collaboration; Monard, Berto; Tang, Yunyi; Dong, Subo; Liu, Zhuokai; Christie, Grant; McCormick, Jennie; Natusch, Tim; Qian, Qiyue; Maoz, Dan; Zhu, Wei; (The MAP; µFUN Follow-up Team); Mróz, Przemek; Szymański, Michał K.; Skowron, Jan; Poleski, Radoslaw; Soszyński, Igor; Pietrukowicz, Paweł; Kozłowski, Szymon; Rybicki, Krzysztof A.; Iwanek, Patryk; Ulaczyk, Krzysztof; Wrona, Marcin; Gromadzki, Mariusz; Mróz, Mateusz J.; OGLE Collaboration; Abe, Fumio; Bando, Ken; Bennett, David P.; Bhattacharya, Aparna; Bond, Ian A.; Fukui, Akihiko; Hamada, Ryusei; Hamada, Shunya; Hamasak, Naoto; Hirao, Yuki; Ishitani Silva, Stela; Koshimoto, Naoki; Matsubara, Yutaka; Miyazaki, Shota; Muraki, Yasushi; Nagai, Tutumi; Nunota, Kansuke; Olmschenk, Greg; Ranc, Clément; Rattenbury, Nicholas J.; Satoh, Yuki; Suzuki, Daisuke; Terry, Sean; Tristram, Paul J.; Vandorou, Aikaterini; Yama, Hibiki; MOA Collaboration
Bibliographical reference
The Astronomical Journal
Advertised on:
1
2026
Citations
4
Refereed citations
0
Description
We present the discovery and analysis of the sixth microlensing two-planet system, KMT-2022-BLG-1818Lb,c, detected by a follow-up program targeting high-magnification events. The second planet was identified from implausible physical parameters for the models with a single planet. Both planets are subject to the well-known "close/wide" degeneracy, although for the first planet, which has a super-Jovian mass ratio of q2 ≃ 5 × 10−3 in both solutions, the close topology, with a normalized separation of s ≃ 0.70, is clearly preferred by ∆χ2 = 26. However, contrary to all previous two-planet microlensing systems, the mass ratio for the second planet, q3, is substantially (factor of ∼10) different for the Close and Wide topologies of the first planet. While this degeneracy is resolved in the present case due to high-cadence follow-up observations, the appearance of this new degeneracy indicates the need for caution in the analysis of future two-planet systems. A Bayesian analysis suggests that the host is likely a K dwarf star in the Galactic disk. The first planet is probably a super-Jupiter on a Jupiter-like orbit, while the second planet is a Saturn-class planet on either a Mercury-like or Saturn-like orbit.