Mapping the Stars with CSST: New Photometric Methods for Measuring Metallicity and Gravity

Lu et al. develop two methods to estimate stellar metallicity and surface gravity using CSST-like photometry. Testing both synthetic and real data, they achieve precisions of about 0.1 dex for metallicity and 0.4 dex for surface gravity. Their “giant–dwarf loci” method performs best, accurately classifying stars and improving metallicity precision. These techniques will enable large-scale stellar characterization with future CSST surveys.