Related papers: Two pairs of interacting EBs towards the LMC in th…
In order to understand the rates and properties of Type Ia and Type Ib/c supernovae, X-ray binaries, gravitational wave sources, and gamma ray bursts as a function of galactic environment and cosmic age, it is imperative that we measure how…
Optical and near-infrared observations are compiled for the three gamma-ray binaries hosting Be stars: PSR B1259-63, LSI+61 303, and HESS J0632+057. The emissions from the Be disk are considered to vary according to the changes in its…
We present a unique discovery of three new detected systems showing two different phenomena together. These are 2+2 quadruple stellar systems showing two eclipsing binaries as the inner pairs. And besides that, these systems were also found…
Eclipse timing variations (ETV) have been a successful tool for detecting circumbinary companions to eclipsing binaries (EB). While TESS and Kepler have been prolific for ETV searches, they sometimes can be limited by time and sky coverage…
We report results from a search for Galactic high-mass eclipsing binaries. The photometric monitoring campaign was performed in Sloan $r$ and $i$ with the robotic twin refractor RoBoTT at the Universit\"atssternwarte Bochum in Chile and…
Low-mass binary millisecond pulsars (LMBPs) are born with very small orbital eccentricities, typically of order $e_i\sim10^{-6}$--$10^{-3}$. In globular clusters, however, higher eccentricities $e_f\gg e_i$ can be induced by dynamical…
The period distribution of contact binaries exhibits a very sharp short period cut-off at 0.22 days. In order to provide valuable information on this short period limit, we observed ten totally eclipsing contact binaries with orbital…
We report the discovery of a binary composed of two brown dwarfs, based on the analysis of the microlensing event OGLE-2016-BLG-1469. Thanks to detection of both finite-source and microlens-parallax effects, we are able to measure both the…
We present a new sample of 4634 eclipsing binary stars in the Large Magellanic Cloud (LMC), expanding on a previous sample of 611 objects and a new sample of 1509 eclipsing binary stars in the Small Magellanic Cloud (SMC), that were…
Long secondary periods (LSPs) in luminous red giants remain the only major class of long-period stellar variability without a secure physical origin. Competing hypotheses include binaries with dusty companions and oscillatory convective…
We report the result of the analysis of the light curve of a caustic-crossing binary-lens microlensing event OGLE-2009-BLG-023/MOA-2009-BLG-028. Even though the event was observed solely by survey experiments, we could uniquely determine…
We report the extremely high magnification (A > 1000) binary microlensing event OGLE-2007-BLG-514. We obtained good coverage around the double peak structure in the light curve via follow-up observations from different observatories. The…
In this work we carry out an analysis of the observed times of primary and secondary eclipses of the post-common envelope binary NSVS14256825. Recently, \cite{Almeida2013} proposed that two circumbinary companions orbit this short-period…
We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the {\it Spitzer Space Telescope}. The light curves seen from the ground and from space exhibit…
A sample of bright contact binary stars (W UMa-type or EW, and related: with beta Lyr light curves, EB, and ellipsoidal, ELL - in effect, all but the detached, EA), to the limit of Vmax = 7.5 magnitude is deemed to include all discoverable…
The Kepler K2 mission now makes it possible to find and study a wider variety of eclipsing binary stars than has been possible to-date, particularly long-period systems with narrow eclipses. Our aim is to characterise eclipsing binary stars…
We present photodynamical models of four eclipsing binary systems that are members of higher-order multiple systems. We provide some radial velocities measurements and use recent TESS data for three of the systems. KIC 7668648 consists of…
Circumbinary planets and brown dwarfs form in complex gravitational environments, offering insights into formation, orbital stability, and habitability prospects. However, they remain underrepresented, with only 60 confirmed or candidate…
Black hole (BH) triples represent one of the astrophysical pathways for BH mergers in the Universe detectable by LIGO and VIRGO. We study the formation of BH triples via binary-binary encounters in dense clusters, showing that one-third of…
Given the stellar density near the galactic center, close encounters between compact object binaries and the supermassive black hole are a plausible occurrence. We present results from a numerical study of close to 13 million such…