We present fundamental atmospheric parameters (Teff and log g) and metallicities ([M/H]) for 507,513 M dwarf stars using low-resolution spectra (R~1800) from LAMOST DR10. By employing Cycle-StarNet, an innovative domain adaptation approach, we successfully bridge the gap between theoretical PHOENIX synthetic spectra and observed LAMOST spectra, enabling parameter measurements even for lower signal-to-noise data (S/N>5). The fitting residual analysis shows a reduction from 2.0 times to 1.68 times the flux uncertainty. Comparing with available literature values, we find systematic offsets and precisions of 12±70 K in Teff, -0.04±0.17 dex in log g, and -0.06±0.20 dex in [M/H]. The precision improves for higher quality spectra (S/N>50) to 47 K, 0.12 dex, and 0.14 dex respectively. The metallicity consistency between wide binaries shows a scatter of 0.24 dex, improving to 0.15 dex at S/N>50. We provide a comprehensive catalog including stellar parameters, spectral classifications, activity indicators, and binary/variability flags, establishing a resource for studies of the most numerous stellar population. The complete catalog is available at https://doi.org/10.5281/zenodo.14030249.
@article{arxiv.2502.01910,
title = {Half a Million M Dwarf Stars Characterized Using Domain-Adapted Spectral Analysis},
author = {Shuo Zhang and Hua-Wei Zhang and Yuan-Sen Ting and Rui Wang and Teaghan O'Briain and Hugh R. A. Jones and Derek Homeier and A-Li Luo},
journal= {arXiv preprint arXiv:2502.01910},
year = {2025}
}