activity
20202026
most citedAn isolated mass gap black hole or neutron star detected with astrometric microlensing

140 citations · 435 across the 49 of their papers we have counts for

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10 papers · 1 filter

astro-ph.SR2025

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…

astro-ph.SR2024

KMT-2021-BLG-0284, KMT-2022-BLG-2480, and KMT-2024-BLG-0412: Three microlensing events involving two lens masses and two source stars

Cheongho Han, Andrzej Udalski, Ian A. Bond +59

We carried out a project involving the systematic analysis of microlensing data from the Korea Microlensing Telescope Network survey. The aim of this project is to identify lensing…

astro-ph.SR2024

Microlensing brown-dwarf companions in binaries detected during the 2022 and 2023 seasons

Cheongho Han, Ian A. Bond, Andrzej Udalski +63

Building on previous works to construct a homogeneous sample of brown dwarfs in binary systems, we investigate microlensing events detected by the Korea Microlensing Telescope Netw…

astro-ph.SR2024

OGLE-2018-BLG-0971, MOA-2023-BLG-065, and OGLE-2023-BLG-0136: Microlensing events with prominent orbital effects

Cheongho Han, Andrzej Udalski, Ian A. Bond +60

We undertake a project to reexamine microlensing data gathered from high-cadence surveys. The aim of the project is to reinvestigate lensing events with light curves exhibiting int…

astro-ph.SR2024

OGLE-2015-BLG-0845L: A low-mass M dwarf from the microlensing parallax and xallarap effects

Zhecheng Hu, Wei Zhu, Andrew Gould +51

We present the analysis of the microlensing event OGLE-2015-BLG-0845, which was affected by both the microlensing parallax and xallarap effects. The former was detected via the sim…

astro-ph.SR2023

Brown dwarf companions in binaries detected from the 2021 season high-cadence microlensing surveys

Cheongho Han, Youn Kil Jung, Ian A. Bond +45

As a part of the project aiming to build a homogeneous sample of binary-lens (2L1S) events containing brown-dwarf (BD) companions, we investigate the 2021 season microlensing data…

astro-ph.SR2023★ 5 cited

Probable brown dwarf companions detected in binary microlensing events during the 2018-2020 seasons of the KMTNet survey

Cheongho Han, Youn Kil Jung, Doeon Kim +48

We inspect the microlensing data of the KMTNet survey collected during the 2018--2020 seasons in order to find lensing events produced by binaries with brown-dwarf companions. In o…

astro-ph.SR2022★ 9 cited

Brown-dwarf companions in microlensing binaries detected during the 2016--2018 seasons

Cheongho Han, Yoon-Hyun Ryu, In-Gu Shin +60

With the aim of finding microlensing binaries containing brown-dwarf (BD) companions, we investigate the microlensing survey data collected during the 2016--2018 seasons. For this…

astro-ph.SR2022

An Isolated Stellar-Mass Black Hole Detected Through Astrometric Microlensing

Kailash C. Sahu, Jay Anderson, Stefano Casertano +90

We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry…

astro-ph.SR2020★ 1 cited

RotNet: Fast and Scalable Estimation of Stellar Rotation Periods Using Convolutional Neural Networks

J. Emmanuel Johnson, Sairam Sundaresan, Tansu Daylan +6

Magnetic activity in stars manifests as dark spots on their surfaces that modulate the brightness observed by telescopes. These light curves contain important information on stella…