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Project Overview
Introduction
Hydrogen exhaustion marks the end of the main sequence for a star. This phase is characterized by the depletion of core hydrogen below a threshold value (typically 10⁻⁵), after which the core contracts and outer layers expand. Our simulations capture this transition in detail, showing how mass and metallicity affect the timing and scale of hydrogen exhaustion.
Discussion
The results reaffirm that stellar evolution is primarily governed by initial mass and metallicity. Higher-mass stars exhaust their hydrogen faster due to higher core temperatures and fusion rates. Lower-metallicity stars tend to be hotter and more luminous at equivalent masses due to reduced opacity. Evolutionary tracks show clear differences in lifetimes, HRD slopes, and core behavior.
Comparison
To validate the simulations, HR diagrams were compared with real observational data from Gaia DR3. The overlay confirms a strong match in the main sequence regime, especially for intermediate-mass stars. Deviations at the low-mass or high-luminosity ends highlight the need for future improvements in modeling stellar winds and rotation.
Conclusion
Simulations until hydrogen exhaustion successfully reproduce classical stellar evolution features. The results highlight consistent trends in HR diagrams, core temperature-density tracks, and main-sequence widths across metallicities. Hydrogen exhaustion serves as a reliable stopping point for observing early stellar evolution.