Related papers: Sodium enhancement in evolved cataclysmic variable…
Building on previous work, we have expanded our catalog of evolutionary models for stars with variable composition; here we present models for stars of mass 0.5 - 1.2 Msol, at scaled metallicities of 0.1 - 1.5 Zsol, and specific C/Fe,…
Some binary systems composed of a white dwarf (WD) and a hot subdwarf (sdB) helium star will make contact within the helium burning lifetime of the sdB star. The accreted helium on the WD inevitably undergoes a thermonuclear instability,…
Cataclysmic Variables (CVs) and Symbiotic Binaries are close (or not so close) binary star systems which contain both a white dwarf (WD) primary and a larger cooler secondary star that typically fills its Roche Lobe. The cooler star is…
Sulfur is one of the most abundant elements in the Universe, yet the sulfur budget inferred from the observed sulfur-bearing molecules in dense cores is significantly lower than expected. Starless and pre-stellar cores represent the…
Trends in the enrichment of elements with stellar ages are a powerful avenue to identify unexplained origins of the elements. We investigate the stellar abundance trends of low to intermediate-mass stars using the GALAH DR3 high-resolution…
The spectrum of the recently discovered cataclysmic variable star (CV) ASAS-SN 13cl shows that a secondary star with spectral type K4 (+- 2 subclasses) contributes roughly half the optical light. The radial velocities of the secondary are…
Chemical abundances of stars in the Milky Way disk are empirical tracers of its enrichment history. However, they capture joint-information that is valuable to disentangle. In this work, we seek to quantify how individual abundances evolve…
The cool temperatures of M dwarf atmospheres enable complex molecular chemistry, making robust characterization of M dwarf compositions a long-standing challenge. Recent modifications to spectral synthesis pipelines have enabled more…
In cataclysmic variables (CVs), accretion onto white dwarfs produces high temperature, high density plasmas. They cool down from kT~10 keV via bremsstrahlung continuum and K and L shell line emissions. The small volume around white dwarfs…
We determine abundance ratios of 37 dwarf ellipticals (dEs) in the nearby Virgo cluster. This sample is representative of the early-type population of galaxies in the absolute magnitude range -19.0 < Mr < -16.0. We analyze their absorption…
We apply the Deloye & Bildsten (2003) isentropic models for donors in ultracompact low-mass X-ray binaries to the AM CVn population of ultracompact, interacting binaries. The mass-radius relations of these systems' donors in the mass range…
Discovery and characterisation of black holes (BHs), neutron stars (NSs), and white dwarfs (WDs) with detached luminous companions (LCs) in wide orbits are exciting because they are important test beds for dark remnant (DR) formation…
The observed orbital period distribution of cataclysmic variables (CVs), the space density derived from observations, and the observed orbital period minimum are known to disagree with theoretical predictions since decades. More recently,…
Recent studies revealed discrepancies between observations and the predictions of the standard magnetic braking (MB). Although alternative models have been broadly discussed in neutron star binaries, they have not been systematically tested…
Ultra-massive white dwarfs ($\rm M_{WD} \gtrsim 1.05\, M_{\odot}$) are considered powerful tools to study type Ia supernovae explosions, merger events, the occurrence of physical processes in the Super Asymptotic Giant Branch (SAGB) phase,…
The discrepancies between observations and theoretical predictions of cataclysmic variables (CVs) suggest that there exists unknown angular momentum loss mechanism(s) besides magnetic braking and gravitational radiation. Mass loss due to…
The 2dF QSO survey is a spectroscopic survey of 48,000 point-sources selected by colour with magnitudes in the range 18.35 < B < 20.95. Amongst QSOs, white dwarfs, narrow-line galaxies and other objects are some cataclysmic variables (CVs).…
Recent observations of quasars show high line-flux ratios in their broad emission lines and the ratios appear to be independent of redshift up to $z \gtrsim 6$, which indicate that the broad-line regions of these early quasars are…
Magnetic cataclysmic variables (CVs) contain a white dwarf with magnetic field strong enough to control the accretion flow from a late type secondary. In this paper, we discover a magnetic CV (CXOGSG J215544.4+380116) from the $Chandra$…
Many observed CEMP stars are found in binary systems and show enhanced abundances of $s$-elements. The origin of the chemical abundances of these CEMP-$s$ stars is believed to be accretion in the past of enriched material from a primary…