TIC star magnetic activity with LAMOST DR10 MRS sp.

We have combined LAMOST medium-resolution spectra with TESS 2 minute light curves and extracted over 530,000 spectra and 110,000 light curves from more than 40,000 stars. We have quantified the H{alpha} line intensity in each spectrum and found that 38,659 spectra from 7002 stars exhibited excess H{alpha} emission and that the intensity of stellar chromospheric activity increases with later spectral types.

We also discovered that the boundary value between the saturated and unsaturated regions of chromospheric activity for different spectral type stars is around Ro=0.1. By analyzing the TESS light curves, we identified 31,539 flare events from 4120 stars. Through these flare events, we determined that the flare-frequency proportion of stars increases with later spectral types.