Results for "R. Poleski"

total 121383took 0.15s
OGLE-2013-BLG-0578L: Microlensing Binary Composed of A Brown Dwarf And An M DwarfMar 11 2015Determining physical parameters of binary microlenses is hampered by the lack of information about the angular Einstein radius due to the difficulty of resolving caustic crossings. In this paper, we present the analysis of the binary microlensing event ... More
ASAS Eclipsing Binaries with Observed High Period Change RatesMar 27 2007We present 31 bright eclipsing contact and semi-detached binaries that showed high period change rates in a 5 year interval in observations by the All-Sky Automated Survey (ASAS). The time-scales of these changes range from only 50 up to 400 kyr. The ... More
OGLE-2014-BLG-0257L: A Microlensing Brown Dwarf Orbiting a Low-mass M DwarfMar 15 2016In this paper, we report the discovery of a binary composed of a brown dwarf and a low-mass M dwarf from the observation of the microlensing event OGLE-2014-BLG-0257. Resolution of the very short-lasting caustic crossing combined with the detection of ... More
Extracting Microlensing Signals from K2 Campaign 9Apr 27 2017Aug 20 2017The 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 work, we present the first method that can extract microlensing signals from ... More
Spitzer as Microlens Parallax Satellite: Mass Measurement for the OGLE-2014-BLG-0124L Planet and its Host StarOct 15 2014We combine Spitzer and ground-based observations to measure the microlens parallax vector ${\mathbf \pi}_{\rm E}$, and so the mass and distance of OGLE-2014-BLG-0124L, making it the first microlensing planetary system with a space-based parallax measurement. ... More
$12\;660$ spotted stars toward the OGLE Galactic bulge fieldsMar 13 2019We present the discovery and statistical analysis of $12\;660$ spotted variable stars toward and inside the Galactic bulge from over two-decade-long Optical Gravitational Lensing Experiment (OGLE) data. We devise a new method of dereddening of individual ... More
The Optical Gravitational Lensing Experiment. Final Reductions of the OGLE-III DataJul 24 2008We describe methods applied to the final photometric reductions and calibrations to the standard system of the images collected during the third phase of the Optical Gravitational Lensing Experiment survey - OGLE-III. Astrometric reduction methods are ... More
The XO Planetary Survey Project - Astrophysical False PositivesJun 10 2010Searches for planetary transits find many astrophysical false positives as a by-product. There are four main types analyzed in the literature: a grazing-incidence eclipsing binary star, an eclipsing binary star with a small radius companion star, a blend ... More
The (non-)variability of magnetic chemically peculiar candidates in the Large Magellanic CloudJul 17 2013The galactic magnetic chemically peculiar (mCP) stars of the upper main sequence are well known as periodic spectral and light variables. The observed variability is obviously caused by the uneven distribution of overabundant chemical elements on the ... More
2009 Superoutburst of Dwarf Nova 1RXS J053234.9+624755Jan 05 2011We present photometric observations of the dwarf nova 1RXS J053234.9+624755. We performed a detailed analysis of the superoutburst that occurred in August 2009. We found the superhump period to be P_sh=0.057122(14)days. Based on the O-C diagram we conclude ... More
Space-based Microlens Parallax Observation As a Way to Resolve the Severe Degeneracy between Microlens-parallax and Lens-orbital EffectJun 04 2016In this paper, we demonstrate the severity of the degeneracy between the microlens-parallax and lens-orbital effects by presenting the analysis of the gravitational binary-lens event OGLE-2015-BLG-0768. Despite the obvious deviation from the model based ... More
A Venus-Mass Planet Orbiting a Brown Dwarf: Missing Link between Planets and MoonsJul 09 2015Jul 13 2015The co-planarity of solar-system planets led Kant to suggest that they formed from an accretion disk, and the discovery of hundreds of such disks around young stars as well as hundreds of co-planar planetary systems by the Kepler satellite demonstrate ... More
Curious Variables Experiment (CURVE). CCD photometry of active dwarf nova DI UMaDec 21 2008Mar 12 2009We report an analysis of photometric behaviour of DI UMa, an extremely active dwarf nova. The observational campaign (completed in 2007) covers five superoutbursts and four normal outbursts. We examined principal parameters of the system to understand ... More
The Scientific Context of WFIRST Microlensing in the 2020sMar 19 2019[abridged] WFIRST is uniquely capable of finding planets with masses as small as Mars at separations comparable to Jupiter, i.e., beyond the current ice lines of their stars. These planets fall between the close-in planets found by Kepler and the wide ... More
Dwarf Nova V1040 Centauri and Variable Stars in its VicinityNov 23 2011Nov 27 2011We present the results of a photometric campaign of the dwarf nova V1040 Cen. The light curve shows two normal outbursts with recurrence time ~ 40 days and amplitude ~ 2.5 mag. Quiescence data show oscillations with periods in the range ~ 0.1 days (2.4 ... More
OGLE-2015-BLG-0051/KMT-2015-BLG-0048Lb: a Giant Planet Orbiting a Low-mass Bulge Star Discovered by High-cadence Microlensing SurveysJun 30 2016We report the discovery of an extrasolar planet detected from the combined data of a microlensing event OGLE-2015-BLG-0051/KMT-2015-BLG-0048 acquired by two microlensing surveys. Despite that the short planetary signal occurred in the very early Bulge ... More
OGLE-2015-BLG-0196: Ground-based Gravitational Microlens Parallax Confirmed By Space-Based ObservationNov 08 2016In this paper, we present the analysis of the binary gravitational microlensing event OGLE-2015-BLG-0196. The event lasted for almost a year and the light curve exhibited significant deviations from the lensing model based on the rectilinear lens-source ... More
"Auxiliary" Science with the WFIRST Microlensing SurveyMar 21 2019The Wide Field Infrared Survey Telescope (WFIRST) will monitor $\sim 2$ deg$^2$ toward the Galactic bulge in a wide ($\sim 1-2~\mu$m) W149 filter at 15-minute cadence with exposure times of $\sim$50s for 6 seasons of 72 days each, for a total $\sim$41,000 ... More
OGLE-2017-BLG-0373Lb: A Jovian Mass-Ratio Planet Exposes A New Accidental Microlensing DegeneracyFeb 27 2018Apr 05 2018We 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 within this topology that fit the data equally well, which leads to a factor ... More
A Super-Jupiter Microlens Planet Characterized by High-Cadence KMTNet Microlensing Survey Observations of OGLE-2015-BLG-0954Feb 29 2016Jun 23 2016We report the characterization of a massive (m_p=3.9 +- 1.4 M_jup) microlensing planet (OGLE-2015-BLG-0954Lb) orbiting an M dwarf host (M=0.33 +- 0.12 M_sun) at a distance toward the Galactic bulge of 0.6 (+0.4,-0.2) kpc, which is extremely nearby by ... More
OGLE-2017-BLG-0537: Microlensing Event with a Resolvable Lens in $\lesssim 5$ years from High-resolution Follow-up ObservationsJun 21 2018We 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 caustic crossing was resolved by high-cadence surveys. It is found that the ... More
A Neptune-mass Free-floating Planet Candidate Discovered by Microlensing SurveysDec 04 2017Feb 13 2018Current microlensing surveys are sensitive to free-floating planets down to Earth-mass objects. All published microlensing events attributed to unbound planets were identified based on their short timescale (below two days), but lacked an angular Einstein ... More
OGLE-2016-BLG-0693LB: Probing the Brown Dwarf Desert with MicrolensingJul 05 2017Sep 27 2017We present an analysis of microlensing event OGLE-2016-BLG-0693, based on the survey-only microlensing observations by the OGLE and KMTNet groups. In order to analyze the light curve, we consider the effects of parallax, orbital motion, and baseline slope, ... More
Masses and Distances of Planetary Microlens Systems with High Angular Resolution ImagingMar 19 2019Microlensing is the only method that can detect and measure mass of wide orbit, low mass, solar system analog exoplanets. Mass measurements of such planets would yield massive science on planet formation, exoplanet demographics, free floating planets, ... More
Target Selection for the SDSS-IV APOGEE-2 SurveyAug 01 2017Sep 18 2017APOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing roughly 300,000 stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV (SDSS-IV). APOGEE-2 is expanding upon APOGEE's goals ... More
Modeling microlensing events with MulensModelMar 02 2018Jan 07 2019We introduce MulensModel, a software package for gravitational microlensing modeling. The package provides a framework for calculating microlensing model magnification curves and goodness-of-fit statistics for microlensing events with single and binary ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. I. Classical Cepheids in the Large Magellanic CloudAug 15 2008Oct 06 2008We present the first part of a new catalog of variable stars (OIII-CVS) compiled from the data collected in the course of the third phase of the Optical Gravitational Lensing Experiment (OGLE-III). In this paper we describe the catalog of 3361 classical ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. VIII. Type II Cepheids in the Small Magellanic CloudMay 19 2010Jul 15 2010The eighth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains type II Cepheids in the Small Magellanic Cloud (SMC). The sample consists of 43 objects, including 17 BL Her, 17 W Vir and 9 RV Tau stars (first examples ever found in the SMC). ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. V. R Coronae Borealis Stars in the Large Magellanic CloudDec 10 2009Feb 04 2010The fifth part of the OGLE-III Catalog of Variable Stars presents 23 R CrB (RCB) stars in the Large Magellanic Cloud (LMC). 17 of these objects have been spectroscopically confirmed by previous studies, while 6 stars are new candidates for RCB variables. ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. III. RR Lyrae Stars in the Large Magellanic CloudMar 13 2009Apr 03 2009The third part of the OGLE-III Catalog of Variable Stars comprises 24906 RR Lyr stars in the Large Magellanic Cloud (LMC). This sample consists of 17693 fundamental-mode (RRab), 4958 first-overtone (RRc), 986 double-mode (RRd) and 1269 suspected second-overtone ... More
The Optical Gravitational Lensing Experiment. OGLE-III Photometric Maps of the Small Magellanic CloudJan 29 2009We present OGLE-III Photometric Maps of the Small Magellanic Cloud. They contain precise, calibrated VI photometry of about 6.2 million stars from 41 OGLE-III fields in the SMC observed regularly in the years 2001-2008 and covering about 14 square degrees ... More
The Optical Gravitational Lensing Experiment. OGLE-III Photometric Maps of the Large Magellanic CloudJul 24 2008We present the OGLE-III Photometric Maps of the Large Magellanic Cloud. They cover about 40 square degrees of the LMC and contain mean, calibrated VI photometry and astrometry of about 35 million stars observed during seven observing seasons of the third ... More
Asymmetric streaming motion in the Galactic bulge X-shaped structure revealed by the OGLE-III proper motionsApr 22 2013The Galactic bulge shows a double red clump in sight lines with |b| > 5 deg and -3 deg < l < 4 deg. It is interpreted as a signature of an X-shaped structure seen almost edge-on. We measure the proper motions of the stars belonging to the closer and the ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. X. Enigmatic Class of Double Periodic Variables in the Large Magellanic CloudSep 27 2010Oct 26 2010The tenth part of the OGLE-III Catalog of Variable Stars contains 125 Double Periodic Variables (DPVs) from the Large Magellanic Cloud. DPVs are semi-detached binaries which show additional variability with a period around 33 times longer than the orbital ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. VII. Classical Cepheids in the Small Magellanic CloudMar 23 2010Apr 01 2010The seventh part of the OGLE-III Catalog of Variable Stars (OIII-CVS) consists of 4630 classical Cepheids in the Small Magellanic Cloud (SMC). The sample includes 2626 fundamental-mode (F), 1644 first-overtone (1O), 83 second-overtone (2O), 59 double-mode ... More
Period Change of Eclipsing Binaries from the ASAS CatalogJul 10 2006We present a preliminary statistical analysis of a period change of eclipsing binaries from the ASAS Catalog of Variable Stars. For each contact and semidetached system brighter than 13.3$mag$ (in V) with a period shorter than 0.4 days and at least 300 ... More
The Optical Gravitational Lensing Experiment. High Proper Motion Stars in the OGLE-III Data for Magellanic Clouds FieldsOct 10 2011We present the results of a search for High Proper Motion (HPM) stars, i.e. the ones with \mu > 100 mas/yr, in the direction to the Magellanic Clouds. This sky area was not examined in detail as the high stellar density hampers efforts in performing high-quality ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. XII. Eclipsing Binary Stars in the Large Magellanic CloudAug 01 2011We present catalog of 26 121 visually inspected eclipsing binary stars identified in the Large Magellanic Cloud during the third phase of the Optical Gravitational Lensing Experiment. The sample is limited to the out-of-eclipse brightness I < 20 mag. ... More
The Optical Gravitational Lensing Experiment. OGLE-III Photometric Maps of the Galactic Bulge FieldsJul 20 2011We present OGLE-III Photometric Maps of the Galactic bulge fields observed during the third phase of the OGLE project. This paper describes the last, concluding set of maps based on OGLE-III data. The maps contain precise, calibrated VI photometry of ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. II. Type II Cepheids and Anomalous Cepheids in the Large Magellanic CloudNov 22 2008Jan 07 2009In the second part of the OGLE-III Catalog of Variable Stars (OIII-CVS) we present 197 type II Cepheids and 83 anomalous Cepheids in the Large Magellanic Cloud (LMC). The sample of type II Cepheids consists of 64 BL Her stars, 96 W Vir stars and 37 RV ... More
OGLE-2014-BLG-1186: gravitational microlensing providing evidence for a planet orbiting the foreground star or for a close binary source?Aug 09 2018(abridged) Using the particularly long gravitational microlensing event OGLE-2014-BLG-1186 with a time-scale $t_\mathrm{E}$ ~ 300 d, we present a methodology for identifying the nature of localised deviations from single-lens point-source light curves, ... More
The Optical Gravitational Lensing Experiment. OGLE-III Photometric Maps of the Galactic Disk FieldsJan 10 2011We present OGLE-III Photometric Maps of the Galactic disk fields observed during the OGLE-III campaigns for low luminosity transiting objects that led to the discovery of the first transiting exoplanets. The maps contain precise, calibrated VI photometry ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. IX. RR Lyrae Stars in the Small Magellanic CloudSep 02 2010Sep 28 2010The ninth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) comprises RR Lyr stars in the Small Magellanic Cloud (SMC). Our sample consists of 2475 variable stars, of which 1933 pulsate in the fundamental mode (RRab), 175 are the first overtone ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. IV. Long-Period Variables in the Large Magellanic CloudOct 07 2009The fourth part of the OGLE-III Catalog of Variable Stars presents 91 995 long-period variables (LPVs) in the Large Magellanic Cloud (LMC). This sample consists of 79 200 OGLE Small Amplitude Red Giants (OSARGs), 11 128 semiregular variables (SRVs) and ... More
The Optical Gravitational Lensing Experiment. Triple-Mode and 1O/3O Double-Mode Cepheids in the Large Magellanic CloudJul 25 2008Oct 06 2008We report the discovery of three new triple-mode classical Cepheids in the Large Magellanic Cloud, two of them with the fundamental, first overtone and second overtone excited, and one pulsating simultaneously in the first three overtones. Thus, the number ... More
The Optical Gravitational Lensing Experiment. The Catalog of Stellar Proper Motions toward the Magellanic CloudsMar 12 2012Apr 25 2012We present a catalog of over 6.2 million stars with measured proper motions. All these stars are observed in the direction of the Magellanic Clouds within the brightness range 12 < I < 19 mag. Based on these proper motions about 440 000 Galactic foreground ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. VI. Delta Scuti Stars in the Large Magellanic CloudApr 06 2010The sixth part of the OGLE-III catalog of Variable Stars presents \delta Sct pulsators in the Large Magellanic Cloud. Altogether 2786 variable stars were found and amongst them 92 are multi-mode objects, including 67 stars pulsating in the fundamental ... More
Blazhko-type modulation in the double-mode RR Lyrae stars of the OGLE Galactic bulge collectionNov 10 2014Dec 16 2014We present the analysis of Blazhko-type modulation in double-mode RR Lyrae (RRd) stars found in the OGLE photometry of the Galactic bulge. Modulation is detected in 15 stars. Most of them have non-typical period ratio of the radial modes. In the Petersen ... More
V1309 Scorpii: merger of a contact binaryDec 01 2010Feb 10 2011Stellar mergers are expected to take place in numerous circumstences in the evolution of stellar systems. In particular, they are considered as a plausible origin of stellar eruptions of the V838 Mon type. V1309 Sco is the most recent eruption of this ... More
OGLE-2002-BLG-360: from a gravitational microlensing candidate to an overlooked red transientApr 05 2013May 16 2013OGLE-2002-BLG-360 was discovered as a microlensing candidate by the OGLE-III project. The subsequent light curve however clearly showed that the brightening of the object could not have resulted from the gravitational microlensing phenomenon. We aim to ... More
Discovery of period doubling in BL Herculis stars of the OGLE survey. Observations and theoretical modelsSep 26 2011We report the discovery of a period doubling behaviour in a 2.4d BL Herculis-type variable of the Galactic bulge. Another bulge BL Her-type star (P=2.25d) is a strong period doubling candidate. Both objects have been identified with the OGLE-III photometry. ... More
The First Neptune Analog or Super-Earth with Neptune-like Orbit: MOA-2013-BLG-605LbDec 01 2015May 12 2016We present the discovery of the first Neptune analog exoplanet or super-Earth with Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that of Neptune or a super-Earth and it orbits at $9\sim 14$ times the expected position of the ... More
OGLE-2016-BLG-1045: A Test of Cheap Space-Based Microlens ParallaxesDec 30 2017Jun 19 2018Microlensing is a powerful and unique technique to probe isolated objects in the Galaxy. To study the characteristics of these interesting objects based on the microlensing method, measurement of the microlens parallax is required to determine the properties ... More
OGLE-2016-BLG-0168 Binary Microlensing Event: Prediction and Confirmation of the Micorlens Parallax Effect from Space-based ObservationJun 01 2017The microlens parallax is a crucial observable for conclusively identifying the nature of lens systems in microlensing events containing or composed of faint (even dark) astronomical objects such as planets, neutron stars, brown dwarfs, and black holes. ... More
First detection of period doubling in a BL Herculis type star. Observations and theoretical modelsNov 30 2011We report on the discovery of the first BL Herculis star displaying period-doubling behaviour as predicted by the hydrodynamic models of Buchler & Moskalik. The star, with P=2.4d, is located in the Galactic bulge and was discovered with OGLE-III photometry. ... More
OGLE-2017-BLG-1130: The First Binary Gravitational Microlens Detected From Spitzer OnlyFeb 25 2018Feb 27 2018We analyze the binary gravitational microlensing event OGLE-2017-BLG-1130 (mass ratio q~0.45), the first published case in which the binary anomaly was only detected by the Spitzer Space Telescope. This event provides strong evidence that some binary ... More
An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2Jul 16 2015Jul 18 2015A detailed analysis is presented of 33 RR Lyrae stars in Pisces observed with the Kepler space telescope over the 8.9-day long K2 Two-Wheel Concept Engineering Test. The sample includes not only fundamental-mode and first overtone (RRab and RRc) stars ... More
New R Coronae Borealis stars discovered in OGLE-III Galactic Bulge fields from their mid- and near- infrared propertiesJul 06 2010Mar 16 2011An R Coronae Borealis (RCB) star is a rare type of supergiant star that is increasingly thought to be the evolved merger product of two white dwarfs. Recently, many of them have been found distributed in a thin disk structure embedded inside the Galactic ... More
OGLE-2013-BLG-0132Lb and OGLE-2013-BLG-1721Lb: Two Saturn-mass Planets Discovered around M-dwarfsMay 02 2017Oct 17 2017We present the discovery of two planetary systems consisting of a Saturn-mass planet orbiting an M-dwarf, which were detected in faint microlensing events OGLE-2013-BLG-0132 and OGLE-2013-BLG-1721. The planetary anomalies were covered with high cadence ... More
OGLE-2015-BLG-1482L: the first isolated low-mass microlens in the Galactic bulgeMar 17 2017Mar 21 2017We 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 finite-source effects due to the passage of the lens close to or directly over ... More
The Variable Stars from the OGLE-III Shallow Survey in the Large Magellanic CloudJun 20 2013We describe variable stars found in the data collected during the OGLE-III Shallow Survey covering the I-band magnitude range from 9.7 mag to 14.5 mag. The main result is the extension of period--luminosity relations for Cepheids up to 134 days. We also ... More
A Likely Detection of a Two-Planet System in a Low Magnification Microlensing EventMar 14 2018We report on the analysis of a microlensing event OGLE-2014-BLG-1722 that showed two distinct short term anomalies. The best fit model to the observed light curves shows that the two anomalies are explained with two planetary mass ratio companions to ... More
Spitzer Opens New Path to Break Classic Degeneracy for Jupiter-Mass Microlensing Planet OGLE-2017-BLG-1140LbMar 12 2018Apr 30 2018We analyze the combined Spitzer and ground-based data for OGLE-2017-BLG-1140 and show that the event was generated by a Jupiter-class $(m_p\simeq 1.6\,M_{\rm jup})$ planet orbiting a mid-late M dwarf $(M\simeq 0.2\,M_\odot)$ that lies $D_{LS}\simeq 1.0\,\mathrm{kpc}$ ... More
Toward a Galactic Distribution of Planets. I. Methodology & Planet Sensitivities of the 2015 High-Cadence Spitzer Microlens SampleJan 18 2017Nov 03 2017We analyze an ensemble of microlensing events from the 2015 Spitzer microlensing campaign, all of which were densely monitored by ground-based high-cadence survey teams. The simultaneous observations from Spitzer and the ground yield measurements of the ... More
OGLE-2016-BLG-1266: A Probable Brown-Dwarf/Planet Binary at the Deuterium Fusion LimitFeb 26 2018We report the discovery, via the microlensing method, of a new very-low-mass binary system. By combining measurements from Earth and from the Spitzer telescope in Earth-trailing orbit, we are able to measure the microlensing parallax of the event, and ... More
OGLE Study of the Sagittarius Dwarf Spheroidal Galaxy and its M54 Globular ClusterMay 16 2016Jul 14 2016We use the fundamental-mode RR Lyr-type variable stars (RRab) from OGLE-IV survey to draw a 3D picture of the central part of the tidally disrupted Sagittarius Dwarf Spheroidal (Sgr dSph) galaxy. We estimate the line-of-sight thickness of the Sgr dSph ... More
No Evidence for Classical Cepheids and a New Dwarf Galaxy Behind the Galactic DiskOct 28 2015Based on data from the ongoing OGLE Galaxy Variability Survey (OGLE GVS) we have verified observed properties of stars detected by the near-infrared VVV survey in a direction near the Galactic plane at longitude l~-27 deg and recently tentatively classified ... More
OGLE Atlas of Classical Novae I. Galactic Bulge ObjectsApr 30 2015Jul 28 2015Eruptions of classical novae are possible sources of lithium formation and gamma-ray emission. Nova remnants can also become Type Ia supernovae (SNe Ia). The contribution of novae to these phenomena depends on nova rates, which are not well established ... More
Period-Luminosity Relations for Ellipsoidal Binary Stars in the OGLE-III Fields of the Large Magellanic CloudDec 08 2014We report the discovery of two distinct types of ellipsoidal binary systems occupying, so called, sequence E on the period-luminosity (P-L) diagram. We propose that steeper P-L relation is composed of giant-dwarf binaries, while the other consists of ... More
The awakening of a classical nova from hibernationAug 16 2016Cataclysmic variable stars (CVs) are close binary systems consisting of a white dwarf (primary) that is accreting matter from a low-mass companion star (secondary). From time to time such systems undergo large-amplitude brightenings. The most spectacular ... More
Over 38000 RR Lyrae Stars in the OGLE Galactic Bulge FieldsOct 06 2014We present the most comprehensive picture ever obtained of the central parts of the Milky Way probed with RR Lyrae variable stars. This is a collection of 38257 RR Lyr stars detected over 182 square degrees monitored photometrically by the Optical Gravitational ... More
Dwarf Novae in the OGLE Data. II. Forty New Dwarf Novae in the OGLE-III Galactic Disk FieldsJul 04 2013Aug 02 2013We report the discovery of forty erupting cataclysmic variable stars in the OGLE-III Galactic disk fields: seventeen objects of U Gem type, four of Z Cam type, and nineteen stars showing outbursts and superoutbursts typical for SU UMa type dwarf novae. ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. XIII. Long-Period Variables in the Small Magellanic CloudSep 06 2011The thirteenth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains 19384 long-period variables (LPVs) detected in the Small Magellanic Cloud. The sample is composed of 352 Mira stars, 2222 semiregular variables (SRVs) and 16810 OGLE Small ... More
Eclipsing Binary Stars in the OGLE-III Galactic Disk FieldsJun 26 2013Aug 02 2013We present the analysis of 11 589 eclipsing binary stars identified in twenty-one OGLE-III Galactic disk fields toward constellations of Carina, Centaurus, and Musca. All eclipsing binaries but 402 objects are new discoveries. The binaries have out-of-eclipse ... More
Photometric Maps Based on the OGLE-III Shallow Survey in the Large Magellanic CloudOct 17 2012We present photometric maps based on data from the shallow survey in the Large Magellanic Cloud performed as the supplementary project during the third phase of the Optical Gravitational Lensing Experiment. They cover about 40 square degrees in the LMC ... More
Quantifying Quasar Variability As Part of a General Approach To Classifying Continuously Varying SourcesSep 07 2009Nov 30 2009Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular transient events (supernovae, novae, microlensing), ... More
Eclipsing Binaries with Classical Cepheid Component in the Magellanic SystemJan 07 2016We present a census of eclipsing binary systems with classical Cepheid as a component. All such systems known were found in the OGLE collection of classical Cepheids in the Magellanic System. We extend the list of potential candidates adding four new ... More
Supernovae and Other Transients in the OGLE-IV Magellanic Bridge DataJan 16 2013Apr 11 2013We analyze two years (mid-2010 to mid-2012) of OGLE-IV data covering ~65 deg^2 of the Magellanic Bridge (the area between the Magellanic Clouds) and find 130 transient events including 126 supernovae (SNe), two foreground dwarf novae and another two SNe-like ... More
The Dusty Aftermath of the V1309 Sco Binary MergerJan 08 2013Jan 10 2013We present mid-IR photometry and spectra of the merged binary V1309 Sco taken between 18 and 23 months after outburst. Strong mid-IR emission and a solid state absorption feature indicate the presence of a significant amount of dust in the circumstellar ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. XI. RR Lyrae Stars in the Galactic BulgeMay 30 2011The eleventh part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains 16836 RR Lyr stars detected in the OGLE fields toward the Galactic bulge. The total sample is composed of 11756 RR Lyr stars pulsating in the fundamental mode (RRab), 4989 ... More
OGLE Collection of Galactic CepheidsOct 22 2018We present here a new major part of the OGLE Collection of Variable Stars - OGLE Collection of Galactic Cepheids. The new dataset was extracted from the Galaxy Variability Survey images - a dedicated large-scale survey of the Galactic disk and outer bulge ... More
OGLE-2016-BLG-0613LABb: A Microlensing Planet in a Binary SystemOct 02 2017We present the analysis of OGLE-2016-BLG-0613, for which the lensing light curve appears to be that of a typical binary-lens event with two caustic spikes but with a discontinuous feature on the trough between the spikes. We find that the discontinuous ... More
Three-Dimensional Distributions of Type II Cepheids and Anomalous Cepheids in the Magellanic Clouds. Do these Stars Belong to the Old, Young or Intermediate-Age Population?Sep 05 2018Oct 24 2018The nature of type II Cepheids and anomalous Cepheids is still not well known and their evolutionary channels leave many unanswered questions. We use complete collection of classical pulsating stars in the Magellanic Clouds discovered by the OGLE project, ... More
The Magellanic Quasars Survey. II. Confirmation of 144 New Active Galactic Nuclei Behind the Southern Edge of the Large Magellanic CloudJun 15 2011Nov 04 2011We quadruple the number of quasars known behind the Large Magellanic Cloud (LMC) from 55 (42 in the LMC fields of the third phase of the Optical Gravitational Lensing Experiment (OGLE)) to 200 by spectroscopically confirming 169 (144 new) quasars from ... More
Gaia and Variable StarsNov 24 2016We present a comparison of the Gaia DR1 samples of pulsating variable stars - Cepheids and RR Lyrae type - with the OGLE Collection of Variable Stars aiming at the characterization of the Gaia mission performance in the stellar variability domain. Out ... More
OGLE-ing the Magellanic System: Photometric Metallicity from Fundamental Mode RR Lyrae StarsJul 29 2016Nov 08 2016In an era of extensive photometric observations, the catalogs of RR Lyr type variable stars number tens of thousands of objects. The relation between the iron abundance [Fe/H] and the Fourier parameters of the stars light curve allows us to investigate ... More
OGLE Atlas of Classical Novae. II. Magellanic CloudsNov 19 2015Jan 07 2016The population of classical novae in the Magellanic Clouds was poorly known because of a lack of systematic studies. There were some suggestions that nova rates per unit mass in the Magellanic Clouds were higher than in any other galaxy. Here, we present ... More
Variability of Massive Stars with Known Spectral Types in the Small Magellanic Cloud Using 8 Years of OGLE-III DataOct 21 2013Jan 20 2014We present a variability study of 4646 massive stars in the Small Magellanic Cloud (SMC) with known spectral types from the catalog of Bonanos et al. (2010) using the light curves from the OGLE-III database. The goal is to exploit the time domain information ... More
One Thousand New Dwarf Novae from the OGLE SurveyJan 11 2016We present one of the largest collections of dwarf novae (DNe) containing 1091 objects that have been discovered in the long-term photometric data from the Optical Gravitational Lensing Experiment (OGLE) survey. They were found in the OGLE fields toward ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. XV. Long-Period Variables in the Galactic BulgeApr 09 2013The fifteenth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains 232,406 long-period variables (LPVs) detected in the OGLE-II and OGLE-III fields toward the Galactic bulge. The sample consists of 6528 Mira stars, 33,235 semiregular variables ... More
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. Type II Cepheids in the Galactic Bulge - SupplementApr 08 2013We report the discovery of additional 22 RV Tau stars located in the OGLE-II and OGLE-III fields toward the Galactic bulge, increasing to 357 objects the OGLE-III catalog of type II Cepheids in the Galactic center. Four of the newly detected RV Tau stars ... More
The Optical Gravitational Lensing Experiment. Optical Counterparts to the X-ray Sources in the Galactic BulgeAug 01 2012We present a sample of 209 variable objects - very likely optical counterparts to the X-ray sources detected in the direction of the Galactic center by the Galactic Bulge Survey (GBS) carried out with the Chandra satellite. The variable sources were found ... More
Large Variety of New Pulsating Stars in the OGLE-III Galactic Disk FieldsNov 22 2013Jan 15 2014We present the results of a search for pulsating stars in the 7.12 deg^2 OGLE-III Galactic disk area in the direction tangent to the Centaurus Arm. We report the identification of 20 Classical Cepheids, 45 RR Lyr type stars, 31 Long-Period Variables, ... More
Recurrent and symbiotic novae in the OGLE dataMay 08 2014Jul 18 2014We analyse long-term optical photometry for two Galactic recurrent novae (V745 Sco and V3890 Sgr) and one Large Magellanic Cloud object (Nova LMC 1990b) observed over several years by the Optical Gravitational Lensing Experiment (OGLE) sky survey. We ... More
The Optical Gravitational Lensing Experiment: Analysis of the bulge RR Lyrae population from the OGLE-III dataJul 15 2011Mar 27 2012We have analyzed the data on 16,836 RR Lyrae (RR Lyr) variables observed toward the Galactic bulge during the third phase of the Optical Gravitational Lensing Experiment (OGLE-III), which took place in 2001-2009. Using these standard candles, we show ... More
The Optical Gravitational Lensing Experiment. Dwarf Novae in the OGLE Data. I. Three New Dwarf Novae: One in the Period Gap and Two Longer Period ObjectsJul 12 2011We report serendipitous discovery of three new dwarf novae which eruptions in 2010 were observed by the ongoing microlensing survey OGLE-IV. All three objects are located in the Galactic bulge fields observed with the highest cadence of 20 minutes. In ... More
The OGLE View of Microlensing towards the Magellanic Clouds. IV. OGLE-III SMC Data and Final Conclusions on MACHOsJun 15 2011In this fourth part of the series presenting the Optical Gravitational Lensing Experiment (OGLE) microlensing studies of the dark matter halo compact objects (MACHOs) we describe results of the OGLE-III monitoring of the Small Magellanic Cloud (SMC). ... More
Multi-Mode and Non-Standard Classical Cepheids in the Magellanic SystemJan 08 2016Jan 19 2016We present a sample of the most interesting classical Cepheids selected from the OGLE collection of classical Cepheids in the Magellanic System. The main selection criterion for this sample was the presence of non-standard, unique pulsational properties. ... More
The First Planetary Microlensing Event with Two Microlensed Source StarsJul 30 2017Mar 22 2018We present the analysis of microlensing event MOA-2010-BLG-117, and show that the light curve can only be explained by the gravitational lensing of a binary source star system by a star with a Jupiter mass ratio planet. It was necessary to modify standard ... More
OGLE-ing the Magellanic System: Photometric Metallicity from Fundamental Mode RR Lyrae StarsJul 29 2016In an era of extensive photometric observations, the catalogs of RR Lyrae type variable stars number tens of thousands of objects. The relation between the iron abundance [Fe/H] and the Fourier parameters of the stars light curve allows us to investigate ... More