The core of the project was solving the coupled differential equations that govern a star's internal structure, describing how pressure, temperature, density, and luminosity evolve with radius. Each equation posed its own challenges: for instance, modeling pressure required incorporating multiple contributions (ideal gas, radiation, and degeneracy pressure), while the temperature profile depended on whether radiative or convective heat transfer was dominant.

To solve the system efficiently, I implemented an adaptive Runge-Kutta method for numerical integration. I built the entire model within a Python class, which allowed for clean parameter management and modular testing. Despite early attempts at modularizing the code with separate files, I found that using a class structure dramatically improved performance, with results generated in seconds compared to failed runs that took over an hour.