235 citations · 4.6k across the 225 of their papers we have counts for
19 papers · 1 filter
A free-floating-planet microlensing event caused by a Saturn-mass object
Subo Dong, Zexuan Wu, Yoon-Hyun Ryu +39
A population of free-floating planets is known from gravitational microlensing surveys. None have a directly measured mass, owing to a degeneracy with the distance, but the populat…
Four Giant Planets from 2024 KMTNet Microlensing Campaign
Cheongho Han, Andrzej Udalski, Ian A. Bond +56
In this work, we present analyses of four newly discovered planetary microlensing events from the 2024 KMTNet survey season: KMT-2024-BLG-0176, KMT-2024-BLG-0349, KMT-2024-BLG-1870…
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…
Three binary-source binary-lens microlensing events from the 2024 microlensing campaign
Cheongho Han, Chung-Uk Lee, Andrzej Udalski +27
We investigated microlensing events detected by the OGLE and KMTNet surveys during the 2024 observing season, focusing on those that exhibit very complex anomaly features. Through…
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…
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…
Systematic Search for FFPs in KMTNet Full-Frame Images. I. Photometry Pipeline
Qiyue Qian, Hongjing Yang, Weicheng Zang +22
To exhume the buried signatures of free-floating planets (FFPs) with small angular Einstein radius , we build a new full-frame difference image pipeline for the Korean M…
LensNet: Enhancing Real-time Microlensing Event Discovery with Recurrent Neural Networks in the Korea Microlensing Telescope Network
Javier Viaña, Kyu-Ha Hwang, Zoë de Beurs +20
Traditional microlensing event vetting methods require highly trained human experts, and the process is both complex and time-consuming. This reliance on manual inspection often le…
MOA-2022-BLG-033Lb, KMT-2023-BLG-0119Lb, and KMT-2023-BLG-1896Lb: Three low mass-ratio microlensing planets detected through dip signals
Cheongho Han, Ian A. Bond, Youn Kil Jung +45
We examined the anomalies in the light curves of the lensing events MOA-2022-BLG-033, KMT-2023-BLG-0119, and KMT-2023-BLG-1896. We conducted detailed modeling of the light curves t…