Publications (28)
Distance to the SMC from eclipsing binaries
Dariusz Graczyk, Grzegorz Pietrzynski, BogumiÅ Pilecki +5
The preliminary distance to a long period eclipsing binary in the Small Magellanic Cloud SMC108.1.14904 is presented. The binary system contains two non-active G-type bright giants…
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…
Blazhko Effect in the first overtone RR Lyrae stars of the OGLE Galactic bulge collection
Henryka Netzel, Radoslaw Smolec, Igor Soszynski +1
We present the analysis of the Blazhko effect - quasi-periodic modulation of pulsation amplitude and/or phase - in the Galactic bulge first overtone RR Lyrae stars (RRc). We used t…
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…
Microlensing optical depth and event rate in the OGLE-IV Galactic plane fields
Przemek Mroz, Andrzej Udalski, Michal K. Szymanski +10
Searches for gravitational microlensing events are traditionally concentrated on the central regions of the Galactic bulge but many microlensing events are expected to occur in the…
Ultra-low Amplitude Variables in the LMC -- Classical Cepheids, Pop. II Cepheids, RV Tau Stars and Binary Variables
J. Robert Buchler, Peter R. Wood, Igor Soszynski
A search for variable stars with ultra-low amplitudes (ULA), in the millimag range, has been made in the combined MACHO and OGLE data bases in the broad vicinity of the Cepheid ins…
A Gas Giant Planet in the OGLE-2006-BLG-284L Stellar Binary System
David P. Bennett, Andrzej Udalski, Ian A. Bond +32
We present the analysis of microlensing event OGLE-2006-BLG-284, which has a lens system that consists of two stars and a gas giant planet with a mass ratio of $q_p = (1.26\pm 0.19…
Interstellar Extinction Curve Variations Toward the Inner Milky Way: A Challenge to Observational Cosmology
David M. Nataf, Oscar A. Gonzalez, Luca Casagrande +18
We investigate interstellar extinction curve variations toward 4 deg of the inner Milky Way in photometry from the OGLE-III and surveys, with supportin…
Ultra-Low Amplitude Cepheids in the Large Magellanic Cloud
J. Robert Buchler, Peter R. Wood, Stefan Keller +1
The MACHO variables of LMC Field 77 that lie in the vicinity of the Cepheid instability strip are reexamined. Among the 144 variables that we identify as Cepheids we find 14 that h…
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…
An X-ray quiet black hole born with a negligible kick in a massive binary within the Large Magellanic Cloud
Tomer Shenar, Hugues Sana, Laurent Mahy +35
Stellar-mass black holes are the final remnants of stars born with more than 15 solar masses. Billions are expected to reside in the Local Group, yet only few are known, mostly det…
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…
An isolated mass gap black hole or neutron star detected with astrometric microlensing
Casey Y. Lam, Jessica R. Lu, Andrzej Udalski +42
We present the analysis of five black hole candidates identified from gravitational microlensing surveys. Hubble Space Telescope astrometric data and densely sampled lightcurves fr…
Modeling of Granulation in Red Supergiants in the Magellanic Clouds with the Gaussian Process Regressions
Zehao Zhang, Yi Ren, Biwei Jiang +2
The granulation of red supergiants (RSGs) in the Magellanic Clouds are systematically investigated by combining the latest RSGs samples and light curves from the Optical Gravitatio…
No large population of unbound or wide-orbit Jupiter-mass planets
Przemek Mroz, Andrzej Udalski, Jan Skowron +9
Gravitational microlensing is the only method capable of exploring the entire population of free-floating planets down to Mars-mass objects, because the microlensing signal does no…
The Tarantula Massive Binary Monitoring VI: Characterisation of hidden companions in 51 single-lined O-type binaries, a flat mass-ratio distribution, and black-hole binary candidates
Tomer Shenar, Hugues Sana, Laurent Mahy +10
We aim to hunt for massive binaries hosting a black hole companion (OB+BH) and establish the natal mass-ratio distribution of massive stars at the subsolar metallicity environment…
HAYDN -- High-precision AsteroseismologY of DeNse stellar fields (ESA Voyage 2050 White Paper)
Andrea Miglio, Leo Girardi, Frank Grundahl +29
In the last decade, the Kepler and CoRoT space-photometry missions have demonstrated the potential of asteroseismology as a novel, versatile and powerful tool to perform exquisite…
OGLE-2017-BLG-1049: Another giant planet microlensing event
Yun Hak Kim, Sun-Ju Chung, A. Udalski +55
We report a giant exoplanet discovery in the microlensing event OGLE-2017-BLG-1049, which is a planet-host star mass ratio of and has a caustic crossin…
A high-velocity bulge RR Lyrae variable on a halo-like orbit
Andrea Kunder, R. Michael Rich, Keith Hawkins +21
We report on the RR Lyrae variable star, MACHO 176.18833.411, located toward the Galactic bulge and observed within the data from the ongoing Bulge RR Lyrae Radial Velocity Assay (…
A Southern Sky and Galactic Plane Survey for Bright Kuiper Belt Objects
Scott Sheppard, Andrzej Udalski, Chad Trujillo +6
About 2500 square degrees of sky south of declination -25 degrees and/or near the galactic plane were surveyed for bright outer solar system objects. This survey is one of the firs…
OGLE-2014-BLG-0319: A Sub-Jupiter-Mass Planetary Event Encountered Degeneracy with Different Mass Ratios and Lens-Source Relative Proper Motions
Shota Miyazaki, Daisuke Suzuki, Andrzej Udalski +36
We report the discovery of a sub-Jovian-mass planet, OGLE-2014-BLG-0319Lb. The characteristics of this planet will be added into a future extended statistical analysis of the Micro…
The Araucaria Project. The distance to the Small Magellanic Cloud from late-type eclipsing binaries
Dariusz Graczyk, Grzegorz Pietrzynski, Ian B. Thompson +12
We present a distance determination to the Small Magellanic Cloud (SMC) based on an analysis of four detached, long period, late type eclipsing binaries discovered by the OGLE Surv…
OGLE-2018-BLG-0532Lb: Cold Neptune With Possible Jovian Sibling
Yoon-Hyun Ryu, Andrzej Udalski, Jennifer C. Yee +34
We report the discovery of the planet OGLE-2018-BLG-0532Lb, with very obvious signatures in the light curve that lead to an estimate of the planet-host mass ratio $q=M_{\rm planet}…
The late type eclipsing binaries in the Large Magellanic Cloud: catalogue of fundamental physical parameters
Dariusz Graczyk, Grzegorz Pietrzynski, Ian B. Thompson +29
We present a determination of precise fundamental physical parameters of twenty detached, double- lined, eclipsing binary stars in the Large Magellanic Cloud (LMC) containing G- or…
A precision determination of the Effect of Metallicity on Cepheid absolute magnitudes in VIJHK bands from Magellanic Cloud Cepheids
Piotr Wielgorski, Grzegorz Pietrzynski, Wolfgang Gieren +8
Using high-quality observed period-luminosity relations in both Magellanic Clouds in VIJHKs bands and optical and near-infrared Wesenheit indices we determine the effect of metalli…
Period-luminosity relations of type II Cepheids in the Magellanic Clouds
Noriyuki Matsunaga, Michael W. Feast, Igor Soszynski
Period-luminosity relations (PLRs) of type II Cepheids (T2Cs) in the Small Magellanic Cloud are derived based on OGLE-III, IRSF/SIRIUS and other data, and these are compared with r…
OGLE-III Microlensing Events and the Structure of the Galactic Bulge
Lukasz Wyrzykowski, Alicja E. Rynkiewicz, Jan Skowron +9
We present and study the largest and the most comprehensive catalog of microlensing events ever constructed. The sample of standard microlensing events comprises 3718 unique events…
The araucaria project. An accurate distance to the late-type double-lined eclipsing binary ogle smc113.3 4007 in the small magellanic cloud
Dariusz Graczyk, Grzegorz Pietrzynski, Ian B. Thompson +13
We have analyzed the long period, double-lined eclipsing binary system OGLE SMC113.3 4007 (SC10 137844) in the SMC. The binary lies in the north-eastern part of the galaxy and cons…