588 citations · 5.8k across the 140 of their papers we have counts for
54 papers · 1 filter
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…
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…
An Orbit for a Massive Wolf-Rayet Binary in the LMC: An Example of Binary Evolution
Breelyn Cocke, Philip Massey, Nidia I. Morrell +6
Wolf-Rayet (WR) stars are helium-burning, evolved massive stars which have had most of their hydrogen-rich outer layers removed either through stellar winds and/or binary stripping…
Be star demographics: a comprehensive study of thousands of lightcurves in the Magellanic Clouds
A. L. Figueiredo, A. C. Carciofi, J. Labadie-Bartz +5
Multi-color OGLE survey light curves of about 20 years duration are analyzed for about 3000 classical Be stars in the Large and Small Magellanic Clouds (LMC, SMC) in order to study…
The dramatic transition of the extreme Red Supergiant WOH G64 to a Yellow Hypergiant
G. Munoz-Sanchez, M. Kalitsounaki, S. de Wit +8
Red Supergiants (RSGs) are cool, evolved massive stars in their final evolutionary stage before exploding as a supernova. However, the evolution and fate of the most luminous RSGs…
Millinovae: A New Class of Transient Supersoft X-ray Sources without a Classical Nova Eruption
Przemek Mróz, Krzysztof Król, Hélène Szegedi +18
Some accreting binary systems containing a white dwarf (such as classical novae or persistent supersoft sources) are seen to emit low-energy X-rays with temperatures of ~10^6 K and…
First Resolution of Microlensed Images of a Binary-Lens Event
Zexuan Wu, Subo Dong, A. Mérand +72
We resolve the multiple images of the binary-lens microlensing event ASASSN-22av using the GRAVITY instrument of the Very Large Telescope Interferometer (VLTI). The light curves sh…
Observational Parameters of Blue Large-amplitude Pulsators
P. Pietrukowicz, M. Latour, I. Soszynski +15
Blue large-amplitude pulsators (BLAPs) are a recently discovered class of short-period pulsating variable stars. In this work, we present new information on these stars based on ph…
Discovery of the Longest-Period Classical Cepheid in the Milky Way
I. Soszyński, D. M. Skowron, A. Udalski +12
We report the discovery of the classical Cepheid OGLE-GD-CEP-1884 (= GDS_J1535467-555656) with the longest pulsation period known in our Galaxy. The period of 78.14 d is nearly 10…
OGLE-2017-BLG-1038: A Possible Brown-dwarf Binary Revealed by Spitzer Microlensing Parallax
Amber Malpas, Michael D. Albrow, Jennifer C. Yee +41
We report the analysis of microlensing event OGLE-2017-BLG-1038, observed by the Optical Gravitational Lensing Experiment, Korean Microlensing Telescope Network, and Spitzer telesc…
Systematic errors as a source of mass discrepancy in black hole microlensing event OGLE-2011-BLG-0462
Przemek Mroz, Andrzej Udalski, Andrew Gould
Two independent groups reported the discovery of an isolated dark stellar remnant in the microlensing event OGLE-2011-BLG-0462 based on photometric ground-based observations couple…
The OGLE Collection of Variable Stars. Nearly 66,000 Mira stars in the Milky Way
Patryk Iwanek, Igor Soszyński, Szymon Kozłowski +12
We present a collection of 65,981 Mira-type variable stars found in the Optical Gravitational Lensing Experiment (OGLE) project database. Two-thirds of our sample (40,356 objects)…
MagAO observations of the binary microlens OGLE-2014-BLG-1050 prefer the higher-mass solution
Xiaojia Xie, Subo Dong, Wei Zhu +9
We report adaptive-optics (AO) follow-up imaging of OGLE-2014-BLG-1050, which is the second binary microlensing event with space-based parallax measurements. The degeneracy in micr…
The OGLE Collection of Variable Stars. One Thousand Heartbeat Stars in the Galactic Bulge and Magellanic Clouds
Marcin Wrona, Milena Ratajczak, Piotr A. Kołaczek-Szymański +13
We present a collection of 991 heartbeat star (HBS) candidates found in the Optical Gravitational Lensing Experiment (OGLE) project data archive. We discuss the selection process o…
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…
Multiwavelength properties of Miras
Patryk Iwanek, Szymon Kozłowski, Mariusz Gromadzki +12
We comprehensively study the variability of Miras in the Large Magellanic Cloud (LMC) by simultaneous analysing light curves in 14 bands in the range of 0.524 microns. We model…
Studies of RR Lyrae Variables in Binary Systems. I.: Evidence of a Trimodal Companion Mass Distribution
Gergely Hajdu, Grzegorz Pietrzyński, Johanna Jurcsik +6
We present 87 candidates for RR Lyrae variable stars in binary systems, based on our new search using the light-travel time effect (LTTE) and observed - calculated () diagrams…
Binarity as the Origin of Long Secondary Periods in Red Giant Stars
I. Soszyński, A. Olechowska, M. Ratajczak +13
Long secondary periods (LSPs), observed in a third of pulsating red giant stars, are the only unexplained type of large-amplitude stellar variability known at this time. Here we sh…
OGLE-GAL-ACEP-091 -- The First Known Multi-Mode Anomalous Cepheid
I. Soszyński, R. Smolec, A. Udalski +12
Anomalous Cepheids (ACs) are metal-deficient, core-helium-burning pulsating stars with masses in the range 1.2-2.2 M_S. Until recently, all known ACs were pure single-mode pulsator…
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…
The Cluster Ages Experiment (CASE). VIII. Age and Distance of the Globular Cluster 47 Tuc from the Analysis of Two Detached Eclipsing Binaries
I. B. Thompson, A. Udalski, A. Dotter +20
We use photometric and spectroscopic observations of the eclipsing binary E32 in the globular cluster 47 Tuc to derive the masses, radii, and luminosities of the component stars. T…
V346 Nor: the post-outburst life of a peculiar young eruptive star
Á. Kóspál, Zs. M. Szabó, P. Ábrahám +5
FU Orionis-type objects (FUors) are young low-mass stars undergoing powerful accretion outbursts. The increased accretion is often accompanied by collimated jets and energetic, lar…
Microlensing optical depth and event rate toward the Galactic bulge from 8 yr of OGLE-IV observations
P. Mroz, A. Udalski, J. Skowron +9
The number and properties of observed gravitational microlensing events depend on the distribution and kinematics of stars and other compact objects along the line of sight. In par…
Type II Cepheids Pulsating in the First Overtone from the OGLE Survey
I. Soszyński, R. Smolec, A. Udalski +1
We report the discovery of the first type II Cepheids (BL Herculis stars) pulsating solely in the first overtone. We found two such objects among tens of millions of stars regularl…