collaborators

11 papers

astro-ph.EP2026

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…

astro-ph.SR2026

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…

astro-ph.EP2025

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…

astro-ph.GA2025

Microlensing optical depth, event rate, and limits on compact objects in dark matter based on 20 yr of OGLE observations of the Small Magellanic Cloud

P. Mróz, A. Udalski, M. K. Szymański +12

Some previous studies have suggested that massive and intermediate-mass primordial black holes (PBHs) could comprise a substantial fraction of dark matter in the Universe. Such bla…

astro-ph.SR2025

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…

astro-ph.EP2025

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…