Related papers: Automated supervised classification of variable st…

We present period-luminosity relations for more than 3,200 red variable stars in the Small Magellanic Cloud observed in the second phase of the Optical Gravitational Lensing Experiment (OGLE-II). Periods of multiply-periodic light curve…

With the advent of digital astronomy, new benefits and new problems have been presented to the modern day astronomer. While data can be captured in a more efficient and accurate manor using digital means, the efficiency of data retrieval…

We 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…

Starting from recent determination of Fe, O, Na abundance on a restricted sample (N=67) of halo and thick disk stars, a natural and well motivated selection criterion is defined for the classification of globular cluster stars. An…

BVI photometry of the Magellanic Clouds collected during the OGLE-II microlensing experiment makes it possible to study in detail photometric properties of the "major" stellar distance indicators in the Magellanic Clouds. In addition to…

There exist a variety of star-galaxy classification techniques, each with their own strengths and weaknesses. In this paper, we present a novel meta-classification framework that combines and fully exploits different techniques to produce a…

The 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…

During the last decade, considerable effort has been made to perform automatic classification of variable stars using machine learning techniques. Traditionally, light curves are represented as a vector of descriptors or features used as…

The list of 127 eclipsing stars in optical coincidence with star clusters from the SMC is presented. It was prepared using the catalogs of eclipsing systems and star clusters from the SMC based on observations collected during the OGLE-II…

In this work we explore the possibility of applying machine learning methods designed for one-dimensional problems to the task of galaxy image classification. The algorithms used for image classification typically rely on multiple costly…

Variable star analysis and classification is an important task in the understanding of stellar features and processes. While historically classifications have been done manually by highly skilled experts, the recent and rapid expansion in…

We search OGLE-I photometric database for stars, which, as defined by formal criteria adopted by OGLE-I microlensing search, showed variability during only one out of 3 or 4 observing seasons. The results include 17 previously reported…

We use the extended and updated OGLE Collection of Variable Stars to thoroughly analyze distribution of RR Lyrae stars in the Magellanic Bridge. We use photometric metallicities to derive absolute Wesenheit magnitude and then individual…

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 of the HBS candidates and the structure of the catalog…

We analyse photometry of $\sim$2000 Galactic Cepheids available in the OGLE Collection of Variable Stars. We analyse both Galactic disk and Galactic bulge fields; stars classified both as single- and multi-periodic. Our goal was to search…

Most galaxies in the nearby Universe are gravitationally bound to a cluster or group of galaxies. Their optical contents, such as optical richness, are crucial for understanding the co-evolution of galaxies and large-scale structures in…

(abridged) In the last decade, the advent of enormous galaxy surveys has motivated the development of automated morphological classification schemes to deal with large data volumes. Existing automated schemes can successfully distinguish…

Stellar rotation, a key factor influencing stellar structure and evolution, also drives magnetic activity, which is manifested as spots or flares on stellar surface. Here, we present a collection of 18 443 rotating variables located toward…

I present an implementation of the difference image photometry based on the Alard & Lupton optimal PSF matching algorithm. The most important feature distinguishing this method from the ones using Fourier divisions is that equations are…

We present a study of photometric properties of very crowded stellar fields toward the Galactic Bulge. We performed a search for pulsating stars among thousands of variable stars from the OGLE-II survey supplementing the variability study…