Related papers: KIC 9272276: An Extreme Low Mass Ratio Red Nova Pr…
Searching for the presence of a circumstellar medium is a direct observational way to discriminate between different types of progenitor systems for Type Ia supernovae. We have modeled whether such gas may give rise to detectable emission,…
The first photometric, spectroscopic, and period variation studies of neglected short-period eclipsing binary V2840 Cygni are presented. High Mass Ratio Contact Binaries, especially those in the weak-contact configuration are vital while…
Contact binaries are close binary systems in which both components fill their inner Roche lobes so that the stars are in direct contact and in potential mass and energy exchange. The most common such systems of low-mass are the so-called W…
Motivated by the existence of binary systems where a stellar-mass black hole is bound to a normal star, we selected four red giants with large radial velocity (RV) variation from the survey of SIM grid stars and monitored their RVs for…
The only well-studied red nova progenitor (V1309 Sco) was a contact binary with a 1.4-day period. The prospects for searching for similar systems, as well as stellar merger candidates in general, are explored in this work. The photospheric…
KIC 6131659 is a long-period (17.5 days) eclipsing binary discovered by the Kepler mission. We analyzed six quarters of Kepler data along with supporting ground-based photometric and spectroscopic data to obtain accurate values for the mass…
High-precision light curves were extracted from TESScut images. Together with APOGEE and LAMOST medium resolution spectra, a joint study was made for six early K-type contact binary candidates selected unbiasedly with orbital periods around…
We present the physical properties of KIC 5621294 showing light and timing variations from the ${\it Kepler}$ photometry. Its light curve displays partial eclipses and O'Connell effect with Max II fainter than Max I, which was fitted quite…
We present a study of a young (few years old) supernova remnant 2003lx which was first discovered in X-ray through two serendipitous Swift observations in 2008 January and the corresponding merged image revealed a 7\sigma source detection…
Type II supernova progenitors are expected to emit copious amounts of mass in a dense stellar wind prior to the explosion. When the progenitor is a member of a binary, the orbital motion modulates the density of this wind. When the…
Studies of fundamental parameters of very low-mass objects are indispensable to provide tests of stellar evolution models that are used to derive theoretical masses of brown dwarfs and planets. However, only objects with dynamically…
Context. Our knowledge of populations and occurrence of planets orbiting evolved intermediate-mass stars is still incomplete. In 2010 we started a planet-search program among 95 giant stars observed by the Kepler mission to increase the…
Recently, the LIGO-Virgo collaboration reported their first detection of gravitational wave (GW) signals from a low mass compact binary merger GW170817, which is most likely due to a double neutron star (NS) merger. With the GW signals…
The detection of O- and B-type stars with extremely low-mass companions is very important for understanding the formation and evolution of binary stars. However, their finding remains a challenge because the low-mass components in such…
Context: It has been predicted that the object KIC 9832227 - a contact binary star - will undergo a merger in 2022.2+/-0.7. We describe the near infrared spectrum of this object as an impetus to obtain pre-merger data. Aims: We aim to…
Adaptive optics corrected images obtained with the CIAO instrument at the Subaru 8.2-meter telescope show the presence of two subarsecond companions to the nearby (d=19.3 pc) young star GJ 900, which was previously classified as a single…
Context. Typical uncertainties of ages determined for single star giants from isochrone fitting using single-epoch spectroscopy and photometry without any additional constraints are 30-50 %. Binary systems, particularly double-lined…
The first binary neutron star merger, GW170817, was accompanied by a radioactivity-powered optical/infrared transient called a kilonova. To date, no compelling kilonova has been found during optical surveys of the sky, independent of…
Ultra-short orbital period contact binaries (Porb < 0.26 d) host some of the smallest and least massive stars. These systems are faint and rare, and it is believed that they have reached a contact configuration after several Gyrs of…
Low-mass stars in eclipsing binary systems show radii larger and effective temperatures lower than theoretical stellar models predict for isolated stars with the same masses. Eclipsing binaries with low-mass components are hard to find due…