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The Clusters AgeS Experiment (CASE). Variable stars in the field of the globular cluster NGC 362

Thompson, I. B.; Schwarzenberg-Czerny, A.; Rozyczka, M. +2 more

The field of the globular cluster NGC 362 was monitored between 1997 and 2015 in a search for variable stars. BV light curves were obtained for 151 periodic or likely periodic variable stars, over a hundred of which are new detections. Twelve newly detected variable stars are proper-motion members of the cluster: two SX Phe and two RR Lyr pulsator…

Gaia and Variable Stars

Soszyński, I.; Udalski, A.; Szymański, M. K. +9 more

We present a comparison of the Gaia DR1 samples of pulsating variable stars - Cepheids and RR Lyr type - with the OGLE Collection of Variable Stars aiming at the characterization of the Gaia mission performance in the stellar variability domain.

Out of 575 Cepheids and 2322 RR Lyr candidates from the Gaia DR1 samples located in the OGLE footp…

One Thousand New Dwarf Novae from the OGLE Survey

Soszyński, I.; Udalski, A.; Szymański, M. K. +7 more

We 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 the Galactic bulge and the Magellanic Clouds. We analyze basic photometric properties of all sy…

Wide-Field Variability Survey of the Globular Cluster M 79 and a New Period-Luminosity Relation for SX Phe Stars

Kopacki, G.

We present the results of a search for variable stars in a 26×39 arcmin² field around globular cluster M 79 (NGC 1904). The search was made by means of an extended version of image subtraction, which allows us to analyze in a uniform manner CCD frames obtained with different telescopes and cameras of different sizes and resolutions. The…

The Study of Triple Systems V949 Cen, V358 Pup and V1055 Sco

Mašek, M.; Zasche, P.; Juryšek, J. +1 more

The systems V949 Cen, V358 Pup, and V1055 Sco are triples comprised of an eclipsing binary orbiting with a distant visual component on a much longer orbit. The first detailed photometric analysis of these interesting systems was performed using also the archival data from Hipparcos, ASAS, SuperWASP, OMC, and Pi of the Sky surveys. The system V358 …

The Clusters AgeS Experiment (CASE): Variable Stars in the Globular Cluster 47 Tucanae

Thompson, I. B.; Kaluzny, J.; Rozyczka, M. +4 more

Based on over 5400 BV images of 47 Tuc collected between 1998 and 2010 we obtained light curves of 65 variables, 19 of which are newly detected objects. New variables are located mostly just outside the core in a region poorly studied by earlier surveys of the cluster. Among them there are four detached eclipsing binaries and five likely optical c…

Detached Red Giant Eclipsing Binary Twins: Rosetta Stones to the Galactic Bulge

Nataf, D. M.; Gould, A.; Pinsonneault, M. H.

We identify 34 highly-probable detached, red giant eclipsing binary pairs among 315 candidates in Devor's catalog of ≈10 000 OGLE-II eclipsing binaries. We estimate that there should be at least 200 such systems in OGLE-III. We show that spectroscopic measurements of the metallicities and radial-velocity-derived masses of these systems would indep…

On the Apsidal Motion of Thirteen Eclipsing Binaries

Zasche, P.

Main aim of this paper is the first light curve and apsidal motion analysis of thirteen eccentric eclipsing binaries and determination of their basic physical properties. All of the systems were studied by the method of period analysis of times of minima and the light curve analysis. Many new times of minima were derived and collected from the dat…

INTEGRAL Observations of OAO 1657-415: Gamma-Ray Tomography of a B Super Giant

Bulik, T.; Denis, M.; Marcinkowski, R.

OAO 1657-415 is an accreting pulsar in an eclipsing binary system. We analyzed the INTEGRAL core program observations of this object and obtained the eclipse light curve in the soft gamma-ray band between 15 keV and 40 keV. We note that the gamma rays from the pulsar allow to probe the density profile of the outer layers of the B super giant compa…

Variable Stars in the Globular Cluster NGC 6752

Thompson, I. B.; Kaluzny, J.

We report time-series photometry for 16 variable stars located in the central part of the globular cluster NGC 6752. The sample includes 13 newly identified objects. The precision of our differential photometry ranges from 1 mmag at V=14.0 mag to 10 mmag at V=18.0 mag. We detected four low amplitude variables located on the extended horizontal bra…