MOA-2022-BLG-091Lb and KMT-2024-BLG-1209Lb: Microlensing planets detected through weak caustic-crossing signals

Aims . The light curves of the microlensing events MOA-2022-BLG-091 and KMT-2024-BLG-1209 exhibit anomalies with very similar features. These anomalies appear near the peaks of the light curves, where the magnifications are moderately high, and are distinguished by weak caustic-crossing features with minimal distortion while the source remains inside the caustic. To achieve a deeper understanding of these anomalies, we conducted a comprehensive analysis of the lensing events. Methods . We carried out binary-lens modeling with a thorough exploration of the parameter space. This analysis revealed that the anomalies in both events are of planetary origin, although their exact interpretation is complicated by different types of degeneracy. In the case of MOA-2022-BLG-091, the main difficulty in the interpretation of the anomaly arises from a newly identified degeneracy related to the uncertain angle at which the source trajectory intersects the planet–host axis. For KMT-2024-BLG-1209, the interpretation is affected by the previously known inner-outer degeneracy, which leads to ambiguity between solutions in which the source passes through either the inner or outer caustic region relative to the planet host. Results . Bayesian analysis indicates that the planets in both lens systems are giant planets with masses about two to four times that of Jupiter, orbiting early K-type main-sequence stars. Both systems are likely located in the Galactic disk at a distance of around 4 kiloparsecs. The degeneracy in KMT-2024-BLG-1209 is challenging to resolve because it stems from intrinsic similarities in the caustic structures of the degenerate solutions. In contrast, the degeneracy in MOA-2022-BLG-091, which occurs by chance rather than from inherent characteristics, is expected to be resolved by the future space based Roman RGES microlensing survey.

Authors

Institutions

Publication Details

Journal
Astronomy and Astrophysics
Published
2025-06-02
DOI
https://doi.org/10.1051/0004-6361/202554182
Citations
2
Primary Topic
Stellar, planetary, and galactic studies
Type
article
Field-Weighted Citation Impact
2.31
Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

MOA-2022-BLG-091Lb and KMT-2024-BLG-1209Lb: Microlensing planets detected through weak caustic-crossing signals

Sang-Mok Cha, Yongseok Lee, I. Soszyński, Michael D. Albrow et al.
2 citations
Astronomy and Astrophysics
Stellar, planetary, and galactic studies
2.31
article

MOA-2022-BLG-091Lb and KMT-2024-BLG-1209Lb: Microlensing planets detected through weak caustic-crossing signals

Sang-Mok Cha, Yongseok Lee, I. Soszyński, Michael D. Albrow, Weicheng Zang, Hongjing Yang, Yuki Satoh, Sean K. Terry, M. Gromadzki, Kyu‐Ha Hwang, Akihiko Fukui, Shude Mao, Hibiki Yama, ‪Clément Ranc, Naoto Hamasaki, Krzysztof A. Rybicki, D. P. Bennett, M. K. Szymański, J. Skowron, Byeong-Gon Park, R. Poleski, Yoon-Hyun Ryu, Wei Zhu, Yossi Shvartzvald, Ryusei Hamada, Seung‐Lee Kim, Chung‐Uk Lee, Naoki Koshimoto, Sun‐Ju Chung, Cheongho Han, Tanagodchaporn Inyanya, T. Sumi, Aikaterini Vandorou, A. Udalski, Youn Kil Jung, Patryk Iwanek, Shota Miyazaki, Stela Ishitani Silva, I. A. Bond, P. Pietrukowicz, P. Mróz, K. Ulaczyk, Nicholas J. Rattenbury, In-Gu Shin, Greg Olmschenk, M. Kiraga, M. Jaroszyński, Yuki Hirao, Dan Maoz, Jennifer C. Yee, Y. Matsubara, Dong-Jin Kim, P. J. Tristram, S. Kozłowski, Richard W. Pogge, Marcin Wrona, Y. Muraki, Mateusz J. Mróz, Kansuke Nunota, Aparna Bhattacharya, Tutumi Nagai, Yunyi Tang, Dong-Joo Lee, Daisuke Suzuki, Fumio Abe, Shunya Hamada, Andrew Gould, Doeon Kim, Ken Bando
article en
2 citations

Abstract

Aims . The light curves of the microlensing events MOA-2022-BLG-091 and KMT-2024-BLG-1209 exhibit anomalies with very similar features. These anomalies appear near the peaks of the light curves, where the magnifications are moderately high, and are distinguished by weak caustic-crossing features with minimal distortion while the source remains inside the caustic. To achieve a deeper understanding of these anomalies, we conducted a comprehensive analysis of the lensing events. Methods . We carried out binary-lens modeling with a thorough exploration of the parameter space. This analysis revealed that the anomalies in both events are of planetary origin, although their exact interpretation is complicated by different types of degeneracy. In the case of MOA-2022-BLG-091, the main difficulty in the interpretation of the anomaly arises from a newly identified degeneracy related to the uncertain angle at which the source trajectory intersects the planet–host axis. For KMT-2024-BLG-1209, the interpretation is affected by the previously known inner-outer degeneracy, which leads to ambiguity between solutions in which the source passes through either the inner or outer caustic region relative to the planet host. Results . Bayesian analysis indicates that the planets in both lens systems are giant planets with masses about two to four times that of Jupiter, orbiting early K-type main-sequence stars. Both systems are likely located in the Galactic disk at a distance of around 4 kiloparsecs. The degeneracy in KMT-2024-BLG-1209 is challenging to resolve because it stems from intrinsic similarities in the caustic structures of the degenerate solutions. In contrast, the degeneracy in MOA-2022-BLG-091, which occurs by chance rather than from inherent characteristics, is expected to be resolved by the future space based Roman RGES microlensing survey.

Astronomy and AstrophysicsVol. 699
Oak Ridge Associated Universities (US), Centre National de la Recherche Scientifique (FR), Goddard Space Flight Center (US), University of Auckland (NZ), Chungbuk National University (KR), Tel Aviv University (IL), University of Canterbury (NZ), Korea Astronomy and Space Science Institute (KR), Japan Aerospace Exploration Agency (JP), Institut d'Astrophysique de Paris (FR), Kyung Hee University (KR), University of Warwick (GB), Sorbonne Université (FR), Center for Astrophysics Harvard & Smithsonian (US), Instituto de Astrofísica de Canarias (ES), Institute of Space and Astronautical Science (JP), University of Warsaw (PL), Massey University (NZ), The Ohio State University (US), Weizmann Institute of Science (IL), Nagoya University (JP), University of Maryland, College Park (US), The University of Tokyo (JP), Villanova University (US), Korea University of Science and Technology (KR), The University of Osaka (JP), Tsinghua University (CN)
Openalex Percentile: Top 12%
Stellar, planetary, and galactic studies
2.31
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.