Related papers: The earliest O-type eclipsing binary in the Small …
Rotational evolution in the pre-main sequence (PMS) is described with new sets of PMS evolutionary tracks including rotation, non-gray boundary conditions (BCs) and either low (LCE) or high convection efficiency (HCE). Using observational…
The surface chemical compositions of stars are affected by physical processes which bring the products of thermonuclear burning to the surface. Despite their potential in understanding the structure and evolution of stars, elemental…
Observations of young star-forming regions suggest that star clusters are born completely mass segregated. These initial conditions are, however, gradually lost as the star cluster evolves dynamically. For star clusters with single stars…
We present results of a systematic investigation of the evolution of low-mass (0.35, 0.40, and 0.65 solar mass) helium donors in semidetached binaries with accretors - white dwarfs. In the initial models of evolutionary sequences abundance…
EL CVn-type binaries contain an A-type dwarf star and a very low mass ($\sim 0.2M_\odot$) helium white dwarf precursor (pre-He WD). Recent surveys and observations have discovered dozens of them, and showed that some pre-He WDs have…
To study the evolution of binary star clusters we have imaged 7 systems in the Small Magellanic Cloud with SOAR 4-m telescope using B and V filters. The sample contains pairs with well-separated components (d < 30 pc) as well as systems…
Liberal evolution of interacting binaries has been proposed previously by several authors in order to meet various observed binary characteristics better than conservative evolution does. Since Algols are eclipsing binaries the distribution…
The theory of binary evolution predicts that many massive stars should lose their hydrogen-rich envelopes via interaction with a companion -- revealing hot helium stars with masses of $\sim$2--8M$_{\odot}$. However, only one candidate…
Massive star feedback affects the evolution of galaxies, where the most massive stars may have the largest impact. The majority of massive stars are born as members of close binary systems. Here, we investigate detailed evolutionary models…
We present a new study of late-type eclipsing binary stars in the Small Magellanic Cloud (SMC) undertaken with the aim of improving the distance determination to this important galaxy. A sample of 10 new detached, double-lined eclipsing…
We highlight the importance of eclipsing double-line binaries in our understanding on star formation and evolution. We review the recent discoveries of low-mass and sub-stellar eclipsing binaries belonging to star-forming regions, open…
V404 Cyg is a Low Mass X-Ray Binary (LMXB) system that has undergone outbursts in 1938, 1989, and 2015. During these events, it has been possible to determine relevant data of the system; such as the masses of the compact object (a black…
We study the formation of massive Population III binary stars using a newly developed radiation hydrodynamics code with the adaptive mesh refinement and adaptive ray-tracing methods. We follow the evolution of a typical primordial…
The multi-color photometric and spectroscopic (based on observations obtained with the T{\"U}B{\.I}TAK National Observatory 1.5-meter telescope, which is owned and operated by the T{\"U}B{\.I}TAK) observations of the newly discovered…
We extend to lower metallicities recent evolutionary computations devoted to Magellanic Clouds stars, presenting and discussing new stellar models with Z=0.0002, 0.0004, 0.0006, 0.001 and suitable assumptions about the original He content.…
Eclipsing binary systems are unique stellar objects to examine and understand the stellar evolution and the formation. Thanks to these systems, the fundamental stellar parameters (mass, radius) can be obtained very precisely. The existence…
NGC 346 is a young cluster with numerous hot OB stars. It is part of the Small Magellanic Cloud (SMC), and has an average metallicity that is one-seventh of the Milky Way's. A detailed study of its stellar content provides a unique…
The recent gravitational wave measurements have demonstrated the existence of stellar mass black hole binaries. It is essential for our understanding of massive star evolution to identify the contribution of binary evolution to the…
The first directly detected gravitational waves (GW 150914) were emitted by two coalescing black holes (BHs) with masses of ~36Msun and ~29Msun. Several scenarios have been proposed to put this detection into an astrophysical context. The…
We study the spectroscopic appearance of very massive stars and their effect on the integrated light of starbursts at low metallicity (Z). We adopt two frameworks for the mass loss rates of VMS: in one case we assume no Z dependence, in the…