79 citations · 806 across the 30 of their papers we have counts for
31 papers
OGLE-2019-BLG-0468Lb,c: two microlensing giant planets around a G-type star
Cheongho Han, Andrzej Udalski, Chung-Uk Lee +37
With the aim of interpreting anomalous lensing events with no suggested models, we conducted a project of reinvestigating microlensing data in and before the 2019 season. In this w…
The Unanticipated Phenomenology of the Blazar PKS~2131021: A Unique Super-Massive Black Hole Binary Candidate
S. O'Neill, S. Kiehlmann, A. C. S. Readhead +24
Most large galaxies host supermassive black holes in their nuclei and are subject to mergers, which can produce a supermassive black hole binary (SMBHB), and hence periodic signatu…
Three faint-source microlensing planets detected via resonant-caustic channel
Cheongho Han, Andrzej Udalski, Doeon Kim +32
We conducted a project of reinvestigating the 2017--2019 microlensing data collected by the high-cadence surveys with the aim of finding planets that were missed due to the deviati…
Using Source Proper Motion to Validate Terrestrial Parallax: OGLE-2019-BLG-1058
In-Gu Shin, Jennifer C. Yee, Kyu-Ha Hwang +30
We show that because the conditions for producing terrestrial microlens parallax (TPRX; i.e., a nearby disk lens) will also tend to produce a large lens-source relative proper moti…
Systematic KMTNet Planetary Anomaly Search, Paper II: Six New Mass-ratio Planets
Kyu-Ha Hwang, Weicheng Zang, Andrew Gould +62
We apply the automated AnomalyFinder algorithm of Paper I (Zang et al. 2021b) to 2018-2019 light curves from the covered by the six KMTNet prime fields, wi…
Three microlensing planets with no caustic-crossing features
Cheongho Han, Andrzej Udalski, Doeon Kim +31
We search for microlensing planets with signals exhibiting no caustic-crossing features, considering the possibility that such signals may be missed due to their weak and featurele…
The ZTF Source Classification Project: I. Methods and Infrastructure
Jan van Roestel, Dmitry A. Duev, Ashish A. Mahabal +18
The Zwicky Transient Facility (ZTF) has been observing the entire northern sky since the start of 2018 down to a magnitude of 20.5 ( for 30s exposure) in , , and fil…
KMT-2018-BLG-1025Lb: microlensing super-Earth planet orbiting a low-mass star
Cheongho Han, Andrzej Udalski, Chung-Uk Lee +32
We aim to find missing microlensing planets hidden in the unanalyzed lensing events of previous survey data. For this purpose, we conduct a systematic inspection of high-magnificat…
The ZTF Source Classification Project: II. Periodicity and variability processing metrics
Michael W. Coughlin, Kevin Burdge, Dmitry A. Duev +22
The current generation of all-sky surveys is rapidly expanding our ability to study variable and transient sources. These surveys, with a variety of sensitivities, cadences, and fi…
Four Microlensing Planets with Faint-source Stars Identified in the 2016 and 2017 Season Data
Cheongho Han, Andrzej Udalski, Doeon Kim +32
Microlensing planets occurring on faint source stars can escape detection due to their weak signals. Occasionally, detections of such planets are not reported due to the difficulty…
OGLE-2018-BLG-1269Lb: A Jovian Planet With A Bright, Host
Youn Kil Jung, Andrew Gould, Andrzej Udalski +54
We report the discovery of a planet in the microlensing event OGLE-2018-BLG-1269, with planet-host mass ratio , i.e., times smaller than the Jupiter/Su…
OGLE-2015-BLG-1771Lb: A Microlens Planet Orbiting an Ultracool Dwarf?
Xiangyu Zhang, Weicheng Zang, Andrzej Udalski +31
We report the discovery and the analysis of the short (tE < 5 days) planetary microlensing event, OGLE-2015-BLG-1771. The event was discovered by the Optical Gravitational Lensing…
Supersoft X-ray emission from a white dwarf binary not powered by nuclear fusion
Thomas J. Maccarone, Thomas J. Nelson, Peter J. Brown +17
Supersoft X-ray sources are stellar objects which emit X-rays with temperatures of about 1 million Kelvin and luminosities well in excess of what can be produced by stellar coronae…
OGLE-2015-BLG-1649Lb: A gas giant planet around a low-mass dwarf
Masayuki Nagakane, Chien-Hsiu Lee, Naoki Koshimoto +66
We report the discovery of an exoplanet in microlensing event OGLE-2015-BLG-1649. The planet/host-star mass ratio is and the projected separation normalized…
Spitzer Microlensing of MOA-2016-BLG-231L : A Counter-Rotating Brown Dwarf Binary in the Galactic Disk
Sun-Ju Chung, Andrew Gould, Jan Skowron +60
We analyze the binary microlensing event MOA-2016-BLG-231, which was observed from the ground and from Spitzer. The lens is composed of very low-mass brown dwarfs (BDs) with $M_1 =…
OGLE-2017-BLG-0537: Microlensing Event with a Resolvable Lens in years from High-resolution Follow-up Observations
Y. K. Jung, C. Han, A. Udalski +29
We present the analysis of the binary-lens microlensing event OGLE-2017-BLG-0537. The light curve of the event exhibits two strong caustic-crossing spikes among which the second ca…
Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-Rotating Low-Mass Brown Dwarf
Yossi Shvartzvald, Jennifer C. Yee, Jan Skowron +63
The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it ca…
Spitzer Opens New Path to Break Classic Degeneracy for Jupiter-Mass Microlensing Planet OGLE-2017-BLG-1140Lb
S. Calchi Novati, J. Skowron, Y. K. Jung +36
We analyze the combined Spitzer and ground-based data for OGLE-2017-BLG-1140 and show that the event was generated by a Jupiter-class planet orbiting…
OGLE-2017-BLG-1522: A giant planet around a brown dwarf located in the Galactic bulge
Y. K. Jung, A. Udalski, A. Gould +27
We report the discovery of a giant planet in the OGLE-2017-BLG-1522 microlensing event. The planetary perturbations were clearly identified by high-cadence survey experiments despi…
OGLE-2017-BLG-0373Lb: A Jovian Mass-Ratio Planet Exposes A New Accidental Microlensing Degeneracy
J. Skowron, Y. -H. Ryu, K. -H. Hwang +30
We report the discovery of microlensing planet OGLE-2017-BLG-0373Lb. We show that while the planet-host system has an unambiguous microlens topology, there are two geometries withi…
Extracting Microlensing Signals from K2 Campaign 9
Wei Zhu, Chelsea Huang, A. Udalski +10
The reduction of the \emph{K2}'s Campaign 9 (K2C9) microlensing data is challenging mostly because of the very crowded field and the unstable pointing of the spacecraft. In this wo…
OGLE-2015-BLG-1482L: the first isolated low-mass microlens in the Galactic bulge
S. -J. Chung, W. Zhu, A. Udalski +35
We analyze the single microlensing event OGLE-2015-BLG-1482 simultaneously observed from two ground-based surveys and from \textit{Spitzer}. The \textit{Spitzer} data exhibit finit…
OGLE-2016-BLG-0596Lb: High-Mass Planet From High-Magnification Pure-Survey Microlensing Event
P. Mróz, C. Han, A. Udalski +24
We report the discovery of a high mass-ratio planet , i.e., 13 times higher than the Jupiter/Sun ratio. The host mass is not presently measured but can be determined or st…
OGLE-2015-BLG-0479LA,B: Binary Gravitational Microlens Characterized by Simultaneous Ground-based and Space-based Observation
C. Han, A. Udalski, A. Gould +60
We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the {\it Spitzer Space Telescope}. T…