MESA and Python files for "Enabling high mass accretion rates onto massive main sequence stars by outer envelope mass removal"

This upload contains a MESA model for an 80 solar mass star that undergoes mass accretion without expanding in radius. The process is done through repeated simulation pulses, each consisting of two steps:

1. Mass and energy accretion (using accretion_inlist) until the radius reaches a set limit.2. Mass removal (using reduction_inlist) to bring the star back to its original radius.

By running multiple pulses, the star can accrete up to ~10% of its initial mass without expanding, as shown in the paper:

Enabling high mass accretion rates onto massive main sequence stars by outer envelope mass removal - Ariel Scolnic, Ealeal Bear, and Noam Soker (2025)

---Inside the provided `.zip` file, you'll find:

1. A starting folder containing the initial MESA model.2. auto_runner.py – A Python script to automate the simulation process.3. accretion_inlist – The inlist for the accretion phase of each pulse.4. reduction_inlist – The inlist for the mass removal phase.

Recommended folder structure before running the script:

main_directory/├── auto_runner.py├── starting_folder/│   ├── LOGS/                 # Latest logs to continue simulations from│   ├── model.mod             # The corresponding .mod file│   ├── accretion_inlist      # Inlist for the accretion phase│   ├── reduction_inlist      # Inlist for the reduction phase

---

To start the simulations, first, create a new main folder and place auto_runner.py along with the starting folder inside. The starting folder should contain the latest LOGS directory, the corresponding .mod file, and accretion_inlist and reduction_inlist files. Open a terminal in the main folder. Run the script by entering python3.11 auto_runner.py and follow the prompts. If continuing from a previous run, confirm when asked. If multiple folders are present, select the correct one to resume from. If the chosen folder contains multiple .mod files, choose the appropriate one. Finally, specify the number of pulses (N) to run. Since each pulse consists of two steps, the script will generate 2N new folders.

---Notes

1. The accretion and reduction phases are structured to keep the star within a set radius.2. If continuing a simulation, ensure the latest `LOGS` folder and `.mod` file are present.3. The script automatically manages folders, creating new ones for each pulse.4. I used MESA version 24.03.1, with SDK version 23.7.3 (Linux, x86_64)