71 citations · 1.8k across the 142 of their papers we have counts for
150 papers
Four Cold Giant Planets Discovered by High-Cadence Microlensing Surveys
Cheongho Han, Chung-Uk Lee, Andrzej Udalski +52
We report the discovery of four cold giant planets identified through the analysis of microlensing events detected by high-cadence surveys: OGLE-2016-BLG-0261, KMT-2025-BLG-0026, K…
Four-Body Gravitational Microlensing Events Involving Both a Binary Lens and a Binary Source
Cheongho Han, Chung-Uk Lee, Andrzej Udalski +31
We present detailed analyses of three anomalous microlensing events--KMT-2021-BLG-0209, KMT-2021-BLG-0901, and OGLE-2025-BLG-0356--identified from a systematic re-examination of KM…
Mass Production of 2023 KMTNet Microlensing Planets. III: Three Planets from the Subprime Field
Hongyu Li, Zhixing Li, Weicheng Zang +56
To complete the analysis of the 2023 KMTNet subprime-field microlensing planetary events identified by its AlertFinder system, we present the analysis of six events, KMT-2023-BLG-(…
Systematic KMTNet Planetary Anomaly Search. XIII. Complete Sample of 2021 Prime Field Planets
In-Gu Shin, Jennifer C. Yee, Weicheng Zang +39
The Systematic KMTNet Planetary Anomaly Search series was conducted using the KMTNet data archived from to . From this first phase of the series, we reported a total o…
Candidate Microlensing Brown Dwarfs in Binary Lens Systems from the 2023--2025 Observing Seasons
Cheongho Han, Andrzej Udalski, Ian A. Bond +62
We present detailed light-curve analyses of ten binary-lens microlensing events observed during the 2023--2025 seasons and selected as candidates for hosting brown-dwarf companions…
Mass Production of 2023 KMTNet Microlensing Planets. II: Two Planets and A Brown Dwarf
Zhixing Li, Hongyu Li, Weicheng Zang +63
To expand the homogeneous microlensing planetary sample of the Korea Microlensing Telescope Network (KMTNet), we investigate six planetary candidates identified by the AnomalyFinde…
Mass Production of 2023 KMTNet Microlensing Planets I: Low Mass Ratio
Yoon-Hyun Ryu, Andrzej Udalski, Hongjing Yang +34
We initiate the systematic search for planets in the 2023 data of the Korea Microlensing Telescope Network (KMTNet), focusing on those planets found by the KMTNet AnomalyFinder wit…
Three Saturn-mass Microlensing Planets Identified through Signals from Peripheral-caustic Perturbations
Cheongho Han, Chung-Uk Lee, Andrzej Udalski +63
We present the discovery and analysis of three microlensing planets identified through brief positive anomalies on the wings of their light curves. The events, KMT-2021-BLG-0852, K…
KMT-2016-BLG-1337L: A Saturn-mass planet orbiting within a binary system of low-mass stars
Cheongho Han, Chung-Uk Lee, Ian A. Bond +55
We report the discovery and characterization of a planetary companion in the microlensing event KMT-2016-BLG-1337, which was produced by a binary system of low-mass stars. The ligh…
Four Cold Super-Jupiters Revealed by Extended and Complex Microlensing Signals
Cheongho Han, Chung-Uk Lee, Michael D. Albrow +18
We present the analysis of four microlensing events, KMT-2020-BLG-0202, KMT-2022-BLG-1551, KMT-2023-BLG-0466, and KMT-2025-BLG-0121, which exhibit extended and complex anomalies in…
Six binary brown dwarf candidates identified by microlensing
Cheongho Han, Chung-Uk Lee, Ian A. Bond +57
In this study, we analyze microlensing events from the 2023 and 2024 observing seasons to identify cases likely caused by binary systems composed of BDs. By applying criteria that…
A Comprehensive Analysis of Three Microlensing Planet Candidates with the Planet/Binary Degeneracy
Jiyuan Zhang, Weicheng Zang, Yoon-Hyun Ryu +65
We present observations and analyses of three high-magnification microlensing events: KMT-2022-BLG-0954, KMT-2024-BLG-0697, and MOA-2024-BLG-018. All three exhibit the "Planet/Bina…
Six microlensing planets detected via sub-day signals during the 2023 -- 2024 season
Cheongho Han, Chung-Uk Lee, Andrzej Udalski +58
We present analyses of six microlensing events: KMT-2023-BLG-0548, KMT-2023-BLG-0830, KMT-2023-BLG-0949, KMT-2024-BLG-1281, KMT-2024-BLG-2059, and KMT-2024-BLG-2242. These were ide…
Four binary microlenses with directly measured masses
Cheongho Han, Andrzej Udalski, Chung-Uk Lee +58
We investigated binary lens events from the 2022-2024 microlensing surveys, aiming to identify events suitable for lens mass measurements. We focused on two key light curve feature…
Towards sub-milliarcsecond astrometric precision using seeing-limited imaging
Noam Segev, Eran O. Ofek, Yossi Shvartzvald +21
The Earth's atmospheric turbulence degrades the precision of ground-based astrometry. Here, we discuss these limitations and propose that, with proper treatment of systematics and…
HST pre-imaging of a free-floating planet candidate microlensing event
Mateusz Kapusta, Przemek Mroz, Yoon-Hyun Ryu +33
High-cadence microlensing observations uncovered a population of very short-timescale microlensing events, which are believed to be caused by the population of free-floating planet…
KMT-2022-BLG-0086: Another binary-lens binary-source microlensing event
Sun-Ju Chung, Kyu-Ha Hwang, Jennifer C. Yee +40
We present the analysis of a microlensing event KMT-2022-BLG-0086 of which the overall light curve is not described by a binary-lens single-source (2L1S) model, which suggests the…
MOA-2022-BLG-091Lb and KMT-2024-BLG-1209Lb: Microlensing planets detected through weak caustic-crossing signals
Cheongho Han, Chung-Uk Lee, Andrzej Udalski +66
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…
KMT-2022-BLG-1818Lb,c: A Cold Super-Jupiter with a Saturn Sibling
Hongyu Li, Jiyuan Zhang, Cheongho Han +72
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. Both…
Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits
Weicheng Zang, Youn Kil Jung, Jennifer C. Yee +65
Exoplanets classified as super-Earths are commonly observed on short period orbits, close to their host stars, but their abundance on wider orbits is poorly constrained. Gravitatio…
Systematic KMTNet Planetary Anomaly Search. XII. Complete Sample of 2017 Subprime Field Planets
Yuqian Gui, Weicheng Zang, Ruocheng Zhai +39
We report the analysis of four unambiguous planets and one possible planet from the subprime fields () of the 2017 Korea Microlensing Telescope Network (KMTN…
Systematic Reanalysis of KMTNet Microlensing Events, Paper II: Two New Planets in Giant-Source Events
Hongjing Yang, Jennifer C. Yee, Jiyuan Zhang +61
In this work, we continue to apply the updated KMTNet tender-love care (TLC) photometric pipeline to historical microlensing events. We apply the pipeline to a subsample of events…
KMTNet View of Blue Large-amplitude Pulsators Toward the Galactic Bulge: I. Discovery of Wide-orbit Companions in OGLE-BLAP-006
Seung-Lee Kim, Chung-Uk Lee, Kyeongsoo Hong +6
Blue large-amplitude pulsators (BLAPs), a recently classified type of variable stars, are evolved objects likely formed through interactions between stars in a binary system. Howev…
Analyses of anomalous lensing events detected from the UKIRT microlensing survey
Cheongho Han, Weicheng Zang, Andrzej Udalski +61
The United Kingdom Infrared Telescope (UKIRT) microlensing survey was conducted over four years, from 2016 to 2019, with the goal of serving as a precursor to future near-infrared…