While many M-dwarfs are known to have strong magnetic fields and high levels of magnetic activity, we are still unsure about the properties of their starspots and the origin of their magnetic dynamos. Both starspots and chromospheric heating are generated by the surface magnetic field; they produce photometric variability and H{alpha} emission, respectively. Connecting brightness variations to magnetic activity therefore provides a means to examine M-dwarf magnetism. We survey 30M dwarfs previously identified as fast rotating stars (Prot<10days). We present time-series optical photometry from the Transiting Exoplanet Survey Satellite (TESS) and contemporaneous optical spectra obtained using the Ohio State Multi-Object Spectrograph (OSMOS) on the 2.4m Hiltner telescope at MDM Observatory in Arizona. We measure rotation periods and photometric amplitudes from TESS light curves using Gaussian Processes. From the OSMOS spectra, we calculate the equivalent width of H{alpha}, and LH{alpha}/Lbol. We find a weak positive correlation between H{alpha} luminosity and the semiamplitude, Rvar (p=0.005_-0.005_^+0.075^). We also observe short-term variability (between 20 and 45minutes) in H{alpha} equivalent widths and possible enhancement from flares consistent to recent literature.

Cone search capability for table J/AJ/165/192/table1 (Parameters for some M-dwarfs in our sample)