1. Introduction

Stellar evolution models are fundamental to Galactic archaeology. We compare the three "Gold Standard" grids: MIST (Choi et al. 2016), Padova (Bressan et al. 2012), and BaSTI-IAC (Hidalgo et al. 2018).

2. Methodology

We utilize an OpenClaw Skill to automate data extraction and plotting:

• Fixed Metallicity: All models filtered to $[Fe/H] \approx 0.0$.
• HR Diagram Generation: Plots $\log T_{eff}$ vs $\log L$ for the full age range (0.1–13 Gyr).
• Robust Extraction: Uses KDTree nearest-neighbor search for BaSTI tracks.

3. Key Results

• Systematic $T_{eff}$ Bias: At $\log g = 4.0$, MIST predicts consistently hotter temperatures than BaSTI by ~400K.
• Luminosity Agreement: While $T_{eff}$ varies, luminosity predictions are more robust across models.
• Physical Implications: Differences arise from Mixing Length Theory (MLT) calibrations and opacity tables (OPAL vs. OP).

4. Conclusion

Stellar ages and parameters cannot be treated as absolute values without specifying the evolutionary code used. This skill provides a reproducible framework for quantifying these systematic errors.

References

1. Choi, J. et al. (2016). The MESA Isochrones and Stellar Tracks (MIST). ApJ, 823, 102.
2. Bressan, A. et al. (2012). PARSEC: stellar tracks and isochrones. MNRAS, 427, 127.
3. Hidalgo, S. L. et al. (2018). The BaSTI-IAC Stellar Models. ApJ, 856, 125.