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Related papers: Evolutionary models for R Coronae Borealis stars

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This study is the direct continuation of the work performed in Hillman et al. (2020) where they used their feedback dominated numerical simulations to model the evolution of four initial models with white dwarf (WD) masses of 0.7 and…

Solar and Stellar Astrophysics · Physics 2021-07-07 Yael Hillman

The evolution of low mass (M < 2.5 Msun) binaries through the common envelope phase has been studied for systems in which one member is on its first ascent of the red giant branch. Three-dimensional hydrodynamical simulations have been…

Astrophysics · Physics 2009-10-31 Eric L. Sandquist , Ronald E. Taam , Andreas Burkert

Stellar evolution theory predicts the existence of He-core remnants of the primary components of intermediate-mass close binaries that lost most of their H/He envelopes due to the mass exchange. They are expected to be observed as (1-7)…

Solar and Stellar Astrophysics · Physics 2024-01-02 L. Yungelson , A. Kuranov , K. Postnov , M. Kuranova , L. Oskinova , W. -R. Hamann

We explore the effects of the residual $\mathrm{^{12}C}$ present in oxygen-neon white dwarfs (ONe WDs) on their evolution towards accretion-induced collapse (AIC). We produce a set of ONe WD models using MESA and illustrate how the amount…

Solar and Stellar Astrophysics · Physics 2019-02-27 Josiah Schwab , Kyle Akira Rocha

A project which aims to understand the abundance patterns of He, C, N, O, Ne, S, and Ar for a small sample of planetary nebulae is described. Abundance ratios of O/H, C/O, and N/O especially show a broad range relative to their solar…

Astrophysics · Physics 2007-05-23 R. B. C. Henry , K. B. Kwitter , J. Buell

(Abridged abstract) We explore the formation of ultra-massive (M_{\rm WD} \gtrsim 1.05 M_\sun$), carbon-oxygen core white dwarfs resulting from single stellar evolution. We also study their evolutionary and pulsational properties and…

Roche-lobe overflow and common envelope evolution are very important in binary evolution, which is believed to be the main evolutionary channel to hot subdwarf stars. The details of these processes are difficult to model, but adiabatic…

Solar and Stellar Astrophysics · Physics 2010-05-19 Hongwei Ge , Ronald F. Webbink , Zhanwen Han , Xuefei Chen

Massive stars often evolve in binary systems, in which binary interactions significantly affect their evolution. Massive stars in the Galaxy serve as valuable testbeds for this due to their proximity. We computed the evolution of more than…

Solar and Stellar Astrophysics · Physics 2026-03-04 Harim Jin , Norbert Langer , Andrea Ercolino , Selma E. de Mink

Two series of models were computed. The first series consists of 20 solar mass models with varying initial metallicity (Z=0.02 down to Z=10^{-8}) and rotation (V_{ini}=0-600 km/s). The second one consists of models with an initial…

Astrophysics · Physics 2007-05-23 Raphael Hirschi

Detached WD+MS PCEBs are perhaps the most suitable objects for testing predictions of close-compact binary-star evolution theories, in particular, CE evolution. The population of WD+MS PCEBs has been simulated by several authors in the past…

Solar and Stellar Astrophysics · Physics 2014-09-05 M. Zorotovic , M. R. Schreiber , E. García-Berro , J. Camacho , S. Torres , A. Rebassa-Mansergas , B. T. Gänsicke

If a massive star has lost significant mass during its red-supergiant stage, it would return to blue region in the HR diagram and spend a part of the core-He burning stage as a blue supergiant having a luminosity to mass ratio (L/M)…

Solar and Stellar Astrophysics · Physics 2013-05-22 Hideyuki Saio , Cyril Georgy , Georges Meynet

We extend to lower metallicities recent evolutionary computations devoted to Magellanic Clouds stars, presenting and discussing new stellar models with Z=0.0002, 0.0004, 0.0006, 0.001 and suitable assumptions about the original He content.…

Astrophysics · Physics 2009-11-10 P. Cariulo , S. Degl'Innocenti , V. Castellani

A significant fraction of all metal-poor stars are carbon-rich. Most of these carbon-enhanced metal-poor (CEMP) stars also show enhancement in elements produced mainly by the s-process (CEMP-s stars) and evidence suggests that the origin of…

Solar and Stellar Astrophysics · Physics 2016-07-13 E. Matrozis , R. J. Stancliffe

The common envelope (CE) interaction between an expanding giant star and a compact companion typically leads to a rapid orbital decay, ending in either a merger or the formation of a close binary. However, the existence of post-red giant…

Solar and Stellar Astrophysics · Physics 2026-04-20 Jack Nibbs , Orsola De Marco , Lionel Siess , Ryosuke Hirai , Daniel Price

The merger of two carbon-oxygen white dwarfs has long been theorized to lead to a massive carbon-oxygen or oxygen-neon white dwarf, accretion-induced collapse to a neutron star, or a type Ia supernova. Determining which mergers lead to a…

Solar and Stellar Astrophysics · Physics 2014-10-20 Chenchong Zhu

We present new fully self-consistent models of the formation and evolution of isolated dwarf galaxies. We have used the publicly available N-body/SPH code HYDRA, to which we have added a set of star formation criteria, and prescriptions for…

Astrophysics · Physics 2009-11-13 Sander Valcke , S. De Rijcke , H. Dejonghe

We present new sets of nonlinear, time-dependent convective hydrodynamical models of RR Lyrae stars assuming two metal (Z=0.0005, Z=0.001) and three helium abundances (Y=0.24, 0.30, 0.38). For each chemical composition we constructed a grid…

Solar and Stellar Astrophysics · Physics 2015-05-28 Marcella Marconi , Giuseppe Bono , Filippina Caputo , Anna M. Piersimoni , Adriano Pietrinferni , Robert F. Stellingwerf

We report estimated carbon-abundance ratios, [C/Fe], for seven newly-discovered carbon-enhanced metal-poor (CEMP) RR Lyrae stars. These are well-studied RRab stars that had previously been selected as CEMP candidates based on low-resolution…

Recently a new class of hot subluminous stars strongly enriched in C and O have been discovered (CO-sdOs). These stars show abundances very similar to those observed in PG1159 stars but at lower temperatures. Moreover, it has been recently…

Solar and Stellar Astrophysics · Physics 2022-02-23 Marcelo M. Miller Bertolami , Tiara Battich , Alejandro H. Córsico , Leandro G. Althaus , Felipe C. Wachlin

Massive stars are key sources of radiative, kinetic, and chemical feedback in the universe. Grids of massive star models computed by different groups each using their own codes, input physics choices and numerical approximations, however,…

Solar and Stellar Astrophysics · Physics 2015-06-23 Samuel Jones , Raphael Hirschi , Marco Pignatari , Alexander Heger , Cyril Georgy , Nobuya Nishimura , Chris Fryer , Falk Herwig