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arXiv · 2607.19175

Identifying and Determining Atmospheric Parameters of BHB Stars Based on LAMOST DR11

Xiao-Long Wang·Wen-Yuan Cui·Jie Ju·Guo-Zhen Hu·Min Fang·Shuai Zhang·Jia-Ming Liu
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Abstract

Large catalogs of blue horizontal-branch (BHB) stars are essential for studying substructures and kinematics of the Galactic halo. And accurate determination of atmospheric parameters for BHB stars provides insight into stellar evolution. In this work, we perform a systematic search for BHB stars based on LAMOST DR11, and identify $13\,988$ BHB spectra, corresponding to $10\,236$ unique BHB stars. We estimate an identification rate of $\sim80\%-90\%$, and a contamination rate of $\lesssim10\%$ for our sample. Atmospheric parameters for these BHB stars are estimated via the data-driven method named the Stellar LAbel Machine (SLAM). We demonstrate the necessity of including color indices in the spectral labeling to effectively break the degeneracy between effective temperature and surface gravity. We note a bump in the distribution of [Fe/H], and most of these metal-rich BHB stars belong to the disk population. We also provide a list of 4282 blue straggler (BS) stars with determined atmospheric parameters.

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Xiao-Long Wang, Wen-Yuan Cui, Jie Ju, Guo-Zhen Hu, Min Fang, Shuai Zhang, Jia-Ming Liu. 2026-07-21. Identifying and Determining Atmospheric Parameters of BHB Stars Based on LAMOST DR11. https://arxiv.org/abs/2607.19175

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