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Related papers: Some Thoughts on the Convective Urca Process

200 papers

The convective kissing instability (CKI) is postulated to occur in low mass stars around the fully convective transition. Non-equilibrium $^{3}$He burning leads to the merging of core and envelope convective zones, which causes abrupt…

Solar and Stellar Astrophysics · Physics 2025-09-23 Conor M. Larsen , James MacDonald

We present a large parameter study where we investigate the structure of white dwarf (WD) merger remnants after the dynamical phase. A wide range of WD masses and compositions are explored and we also probe the effect of different initial…

High Energy Astrophysical Phenomena · Physics 2015-06-16 M. Dan , S. Rosswog , M. Brueggen , P. Podsiadlowski

A hybrid C/O/Ne white dwarf (WD) -- an unburned C/O core surrounded by an O/Ne/Na mantle -- can be formed if the carbon flame is quenched in a super-AGB (SAGB) star or white dwarf merger remnant. We show that this segregated hybrid…

Solar and Stellar Astrophysics · Physics 2017-01-18 Jared Brooks , Josiah Schwab , Lars Bildsten , Eliot Quataert , Bill Paxton

In the far future long after star formation has ceased the universe will be populated by sparse degenerate remnants, mostly white dwarfs, though their ultimate fate is an open question. These white dwarfs will cool and freeze solid into…

High Energy Astrophysical Phenomena · Physics 2020-08-07 M. E. Caplan

In this work, we estimate how much bulk viscosity driven by Urca processes is likely to affect the gravitational wave signal of a neutron star coalescence. In the late inspiral, we show that bulk viscosity affects the binding energy at…

We describe the evolution of double degenerate binary systems, consisting of components obeying the zero temperature mass radius relationship for white dwarf stars, from the onset of mass transfer to one of several possible outcomes…

Astrophysics · Physics 2008-11-26 Vayujeet Gokhale , Xiao Meng Peng , Juhan Frank

We present new white dwarf evolutionary sequences for low-metallicity progenitors. White dwarf sequences have been derived from full evolutionary calculations that take into account the entire history of progenitor stars, including the…

Sub-Neptunes and Neptunes are often modeled with distinct, fully convective layers. Yet, there are several arguments for compositions gradients that can inhibit convection. In these regions, energy transport depends on the thermal…

Earth and Planetary Astrophysics · Physics 2026-05-29 Mark Eberlein , Ravit Helled

Our Galaxy is a complex machine in which several processes operate simultaneously: metal-poor gas is accreted, is chemically enriched by dying stars, and then drifts inwards, surrendering its angular momentum to stars; new stars are formed…

Astrophysics of Galaxies · Physics 2015-06-17 James Binney

A review is presented of some of the ingredients, assumptions and techniques that are used in the computation of the structure and evolution of low-mass stars. Emphasis is placed on several ingredients which are still subject to…

Astrophysics · Physics 2008-11-26 M. Catelan

I review the processes that shape the evolution of protoplanetary discs around young, solar-mass stars. I first discuss observations of protoplanetary discs, and note in particular the constraints these observations place on models of disc…

Astrophysics · Physics 2008-11-26 Richard Alexander

We present new numerical method to compute structures of differentially rotating white dwarfs with thermal stratification. Our models have cores composed of ions and completely degenerate electrons and have isentropic envelopes composed of…

High Energy Astrophysical Phenomena · Physics 2019-04-24 Shin'ichirou Yoshida

Charged current neutrino-nucleon reactions, generally called Urca processes, are crucial actors of a neutron star's thermal evolution. The so-called direct processes show a pronounced threshold under which the reaction is kinematically…

Nuclear Theory · Physics 2026-01-12 Lami Suleiman , Micaela Oertel , Marco Mancini

White dwarfs are the burnt out cores of Sun-like stars and are the final fate of 97% of all stars in our Galaxy. The internal structure and composition of white dwarfs are hidden by their high gravities, which causes all elements, apart…

Based on stellar evolution simulations, we demonstrate that rapidly accreting white dwarfs in close binary systems are an astrophysical site for the intermediate neutron-capture process. During recurrent and very strong He-shell flashes in…

Solar and Stellar Astrophysics · Physics 2017-01-18 Pavel Denissenkov , Falk Herwig , Umberto Battino , Christian Ritter , Marco Pignatari , Samuel Jones , Bill Paxton

We show that the direct Urca process of neutrino emission is allowed in two possible phases of nonspherical nuclei (inverse cylinders and inverse spheres) in the mantle of a neutron star near the crust-core interface. The process is open…

Astrophysics · Physics 2009-11-10 M. E. Gusakov , D. G. Yakovlev , P. Haensel , O. Y. Gnedin

The first part of this paper deals with the impact of nonsolar and - for late-type, dwarf, and high redshift galaxies - generally subsolar abundances on the interpretation of observational data for starburst galaxies. It points out the…

Astrophysics · Physics 2007-05-23 U. Fritze-v. Alvensleben

Several hypervelocity white dwarfs (HVWDs) with space velocities of $\gtrsim 1000\,\mathrm{kms}^{-1}$ have recently been discovered. One possible origin of these stars is the dynamically-driven double-degenerate double-detonation (D6)…

Solar and Stellar Astrophysics · Physics 2025-09-18 Natsuko Yamaguchi , Kareem El-Badry , Tin Long Sunny Wong , Ken J. Shen

Our understanding of the convective-engine paradigm driving core-collapse supernovae has been used for 2 decades to predict the remnant mass distribution from stellar collapse. These predictions improve as our understanding of this engine…

High Energy Astrophysical Phenomena · Physics 2022-06-08 Chris L. Fryer , Aleksandra Olejak , Krzysztof Belczynski

We present the first detailed three-dimensional hydrodynamic implicit large eddy simulations of turbulent convection for carbon burning. The simulations start with an initial radial profile mapped from a carbon burning shell within a 15…

Solar and Stellar Astrophysics · Physics 2017-12-20 Andrea Cristini , Casey Meakin , Raphael Hirschi , David Arnett , Cyril Georgy , Maxime Viallet