We study the properties of double white dwarf (DWD) mergers by performing hydrodynamic
simulations using the new and improved adaptive mesh refinement code octo-tiger. We …

Stellar spectral classification has been highly useful in the study of stars. While there is a
currently accepted spectral classification system for carbon stars, the subset of hydrogen …

Hydrogen-deficient carbon (HdC) stars are rare, low-mass, chemically peculiar, supergiant
variables believed to be formed by a double white dwarf (DWD) merger, specifically of a …

Context. Open clusters are ideal tools for tracing the abundances of different elements
because their stars are expected to have the same age, distance, and metallicity. Therefore …

Ultra-massive white dwarfs (UMWDs) with masses larger than 1.05 M⊙ are basically
believed to harbour oxygen–neon (ONe) cores. Recently, Gaia data have revealed an …

Abstract We use Modules for Experiments in Stellar Astrophysics (MESA) to construct stellar
evolution models that reach a hydrogen-deficient, carbon-rich giant phase like the R …

Abstract Abundances of fluorine (19 F), as well as isotopic ratios of 16 O/17 O, are derived in
a sample of luminous young (∼ 10 7–10 8 yr) red giants in the Galactic center (with …

Double white dwarf (WD) merger process and their post-merger evolution are important in
many fields of astronomy, such as supernovae, gamma-ray bursts, gravitational waves, and …

Context. It is more and more suspected that R Coronae Borealis (RCB) stars–rare hydrogen-
deficient and carbon-rich supergiant stars–are the products of mergers of CO/He white-dwarf …

Abstract R Coronae Borealis (RCB) stars are rare hydrogen-deficient carbon-rich variable
supergiants thought to be the result of dynamically unstable white dwarf mergers. We …