Building three-dimensional giant stellar models for common envelope simulations
Abstract
We build a three-dimensional (3D) red supergiant (RSG) stellar model by transporting a 1D stellar model to a 3D numerical grid, mimicking core nuclear power by depositing energy into an inner shell, and mimicking stellar emission by cooling grid cells with densities below the photospheric density. The goal is to use such models for common envelope evolution (CEE) and grazing envelope evolution simulations. We do not relax the model; rather, we let it perform its natural pulsation. We find that when we mimic photospheric emission by cooling low-density grid cells, the oscillations decay slowly on a timescale much longer than without photospheric cooling. When we mimic both nuclear energy production, by depositing the stellar luminosity in an inner shell above the inert core of the stellar model, and photospheric cooling, the oscillations do not decay; instead, their amplitude slowly increases with time. The main pulsational period is about 1 year, comparable to the stellar dynamical time, suggesting a fundamental radial pulsation mode. The non-spherical structure of the stellar model and rapid low-amplitude temporal variations in the average stellar radius tentatively hint at the presence of non-radial oscillation modes on top of the fundamental radial mode. We also obtain convection, as RSG stars should have. We conclude that energy deposition in the inner envelope at the stellar luminosity and the cooling of the outer low-density numerical cells are a way of preparing a pulsating giant star to simulate CEE and grazing-envelope evolution. This procedure requires no relaxation of the stellar model.
Related
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- Building the Dwarf Nova NS Per in the Young Open Cluster NGC 1528 Requires Inefficient Common-envelope Ejection
- Studies of Two Post Common Envelope Binary Stars
- The Best Guess: Testing New and Old Formalisms for the Common Envelope against Observations
BibTeX
@misc{schreier2026building,
title = {{Building three-dimensional giant stellar models for common envelope simulations}},
author = {Ron Schreier and Shlomi Hillel and Noam Soker},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.11927},
eprint = {2606.11927},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.11927},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Building three-dimensional giant stellar models for common envelope simulations
AU - Ron Schreier
AU - Shlomi Hillel
AU - Noam Soker
PY - 2026
DA - 2026/09/20
PB - arXiv
DO - 10.48550/arxiv.2606.11927
UR - https://arxiv.org/abs/2606.11927
AB - We build a three-dimensional (3D) red supergiant (RSG) stellar model by transporting a 1D stellar model to a 3D numerical grid, mimicking core nuclear power by depositing energy into an inner shell, and mimicking stellar emission by cooling grid cells with densities below the photospheric density. The goal is to use such models for common envelope evolution (CEE) and grazing envelope evolution simulations. We do not relax the model; rather, we let it perform its natural pulsation. We find that when we mimic photospheric emission by cooling low-density grid cells, the oscillations decay slowly on a timescale much longer than without photospheric cooling. When we mimic both nuclear energy production, by depositing the stellar luminosity in an inner shell above the inert core of the stellar model, and photospheric cooling, the oscillations do not decay; instead, their amplitude slowly increases with time. The main pulsational period is about 1 year, comparable to the stellar dynamical time, suggesting a fundamental radial pulsation mode. The non-spherical structure of the stellar model and rapid low-amplitude temporal variations in the average stellar radius tentatively hint at the presence of non-radial oscillation modes on top of the fundamental radial mode. We also obtain convection, as RSG stars should have. We conclude that energy deposition in the inner envelope at the stellar luminosity and the cooling of the outer low-density numerical cells are a way of preparing a pulsating giant star to simulate CEE and grazing-envelope evolution. This procedure requires no relaxation of the stellar model.
ER -