Related papers: Dynamically Forming Extremely Low-Mass White Dwarf…

The origin of highly-magnetized white dwarfs has remained a mystery since their initial discovery. Recent observations indicate that the formation of high-field magnetic white dwarfs is intimately related to strong binary interactions…

As the descendants of stars with masses less than 8 M$_{\odot}$ on the main sequence, white dwarfs provide a unique way to constrain planetary occurrence around intermediate-mass stars (spectral types BAF) that are otherwise difficult to…

Blue straggler stars (BSSs) are formed through mass transfer or mergers in binaries. The recent detections of white dwarf (WD) companions to BSSs in M67 suggested a mass transfer pathway of formation. In search of a close companion to five…

We have performed detailed numerical calculations of the non-conservative evolution of close binary systems with low-mass (1.0-2.0 M_sun) donor stars and a 1.3 M_sun accreting neutron star. Rather than using analytical expressions for…

The majority of stars both host planetary systems and evolve into a white dwarf (WD). To understand their post-main-sequence (PMS) planetary system evolution, we present a search for transiting/eclipsing planets and other Substellar Bodies…

Eclipsing close double white dwarf (WD) systems provide a unique opportunity to directly constrain hydrogen-envelope retention and test common-envelope (CE) evolution in low-mass stars, since they allow precise determinations of stellar…

Hot subdwarf B stars (sdBs) in close binary systems are assumed to be formed via common envelope ejection. According to theoretical models, the amount of energy and angular momentum deposited in the common envelope scales with the mass of…

We propose and analyze a new mechanism for the formation of the wide asynchronous binary population. These binary asteroids have wide semi-major axes relative to most near-Earth and Main Belt asteroid systems. Confirmed members have rapidly…

WR 31a (Hen 3-519) is likely a post-luminous blue variable (LBV) star that is evolving to become a classical Wolf-Rayet star. Multicolor (UBVR) photopolarimetric observations of WR 31a were obtained over nine nights in early 2007. The…

We investigate the hypothesis that stars form in aggregates of binary systems and that the dynamical evolution of these aggregates leads to the observed properties of binary stars in the Galactic field. We assume that the initial…

Low-mass white dwarfs (LMWDs) are believed to be exclusive products of binary evolution, as the Universe is not yet old enough to produce them from single stars. Because of the strong tidal forces operating during the binary interaction…

Binary evolution theory predicts that the second common envelope (CE) ejection can produce low-mass (0.32-0.36 Msun) subdwarf B (sdB) stars inside ultrashort-orbital-period binary systems, as their helium cores are ignited under…

The merger of close double white dwarfs (CDWDs) is one of the favourite evolutionary channels for producing Type Ia supernovae (SN Ia). Unfortunately, current theories of the evolution and formation of CDWDs are still poorly constrained and…

We present the results of a 3.5 year long campaign to measure orbital periods of subdwarf B (sdB) star binaries. We directly compare our observed orbital period distribution with that predicted by using binary population synthesis. Up to…

A White Dwarf (WD) star and a main-sequence companion may interact through their different stellar evolution stages. This sort of binary population has historically helped us improve our understanding of binary formation and evolution…

We postulate that most stars are born in aggregates of binary systems which are dynamically equivalent to the `dominant mode cluster'. The initial binary orbits are consitent with pre-main sequence data. Stellar masses are paired at random…

The most frequently seen binary companions to millisecond pulsars (MSPs) are helium white dwarfs (He WDs). The standard rejuvenation mechanism, in which a low- to intermediate-mass companion to a neutron star fills its Roche lobe between…

The recent discoveries of WD J091405.30+191412.25 (WD J0914 hereafter), a white dwarf likely accreting material from an ice giant planet, and WD 1856+534 b (WD 1856 b hereafter), a Jupiter-sized planet transiting a white dwarf, are the…

We report the discovery of EPIC201702477b, a transiting brown dwarf in a long period (40.73691 +/- 0.00037 day) and eccentric (e=0.2281 +/- 0.0026) orbit. This system was initially reported as a planetary candidate based on two transit…

White dwarfs represent the last stage of evolution of stars with mass less than about eight times that of the Sun and, like other stars, are often found in binaries. If the orbital period of the binary is short enough, energy losses from…