Related papers: The White Dwarf Binary Pathways Survey III: contam…

Double white dwarf (DWD) binaries are important for studies of common-envelope (CE) evolution, Type Ia supernova progenitors and Galactic sources of low-frequency gravitational waves (GWs). PTF J0533+0209 is a DWD system with a short…

Hot subdwarfs (sdBs) are core helium-burning stars, which lost almost their entire hydrogen envelope in the red-giant phase. Since a high fraction of those stars are in close binary systems, common envelope ejection is an important…

Increasing observations of white dwarf atmospheric pollution and disrupting planetesimals is driving increased studies into the fate of exo-asteroids around post-main-sequence stars. Planetesimal populations in the Solar System which are…

Binary systems containing a magnetic white dwarf and a main-sequence star are considered extremely rare, perhaps non-existent. In the course of a search of magnetic fields in high-mass white dwarfs we have discovered a Sirius-like wide…

We present the spectroscopic orbits of eleven nearby, mid-to-late M dwarf binary systems in a variety of configurations: two single-lined binaries (SB1s), seven double-lined binaries (SB2s), one double-lined triple (ST2), and one…

Planets and stars ultimately form out of the collapse of the same cloud of gas. Whilst planets, and planetary bodies, readily loose volatiles, a common hypothesis is that they retain the same refractory composition as their host star. This…

We describe spectroscopic observations of 21 low-mass (<0.45 M_sun) white dwarfs (WDs) from the Palomar-Green Survey obtained over four years. We use both radial velocities and infrared photometry to identify binary systems, and find that…

We find that $\sim 15-20$ per cent of A-type stars or red giants are bound with a massive companion ($M_{\rm secondary} > 1M_{\odot}$) in an intermediate wide orbit ($0.5<P<5000\mbox{ yr}$). These massive binaries are expected to form…

We have measured the orbital parameters of seven close binaries, including six new objects, in a radial velocity survey of 38 objects comprising a hot subdwarf star with orbital periods ranging from ~0.17 to 3 d. One new system, GALEX…

Practically all known planet hosts will evolve into white dwarfs, and large parts of their planetary systems will survive this transition - the same is true for the solar system beyond the orbit of Mars. Spectroscopy of white dwarfs…

A-stars are the progenitors of about half of the white dwarfs (WDs) that currently exist. The connection between the multiplicity of A-stars and that of WDs is not known and the observational mapping of both multiplicities are far from…

[Abridged]We investigate the long-term secular dynamics and Lidov-Kozai(LK) eccentricity oscillations of quadruple systems composed of two binaries at quadrupole and octupole order in the perturbing Hamiltonian. We show that the fraction of…

Characterizing the local space density of double degenerate binary systems is a complementary approach to broad sky surveys of double degenerates to determine the expected rates of white dwarf binary mergers, in particular those that may…

We present a long-term programme for timing the eclipses of white dwarfs in close binaries to measure apparent and/or real variations in their orbital periods. Our programme includes 67 close binaries, both detached and semi-detached and…

For sufficiently wide orbital separations {\it a}, the two members of a stellar binary evolve independently. This implies that in a wide double white dwarf (DWD), the more massive WD should always be produced first, when its more massive…

The formation channels and predicted populations of double-white dwarfs (DWDs) are important because a subset will evolve to be gravitational-wave sources and/or progenitors of Type Ia supernovae. Given the observed population of…

We present Hubble Space Telescope far-ultraviolet (FUV) spectra of a blue-lurker$-$white-dwarf (BL-WD) binary system in the 4 Gyr open cluster M67. We fit the FUV spectrum of the WD, determining it is a C/O WD with a mass of…

Approximately 150 low-mass white dwarfs, with masses below 0.4Msun, have been discovered. The majority of these low-mass WDs are observed in binary systems as they cannot be formed through single-star evolution within the Hubble time. In…

White dwarfs (WDs) receive natal velocity boosts of $\sim 1 \, \mathrm{km \, s^{-1}}$ due to recoil from asymmetric mass loss during the late asymptotic giant branch (AGB) stage. In a wide binary, the acceleration of a proto-WD exerts a…

We determine the possible masses and radii of the progenitors of white dwarfs in binaries from fits to detailed stellar evolution models and use these to reconstruct the mass-transfer phase in which the white dwarf was formed. We confirm…