  M dwarf stars comprise 70-80% of the galaxy's stars and host most of its
rocky planets. They also importantly differ from Sunlike stars in that they are
"active" for billions of years or more: rotating quickly, flaring often, and
emitting large amounts of UV and X-ray light. The effects of stellar activity
upon both photometry and spectroscopy make their exoplanets more difficult to
detect, and M dwarfs exhibit this behavior for thousands of times longer than a
typical Sunlike star. While activity signals such as flaring and stellar
rotation can be more readily modeled or removed from photometry, the
contribution of unresolved stellar activity to transit sensitivity is harder to
quantify. In this paper, we investigate the difference in the detectability of
planetary transits around a sample of M dwarfs observed by NASA's TESS Mission,
characterized by a common stellar radius, effective temperature, and TESS
magnitude. Our sample is classified as either "active" or "inactive" based upon
the presence of H$\alpha$ in emission. After removing the more readily
identifiable signatures of activity: stellar rotation and large flares, we
perform an injection-and-recovery analysis of transits for each star. We
extract detection sensitivity as a function of planetary radius and orbital
period for each star in the sample. Then, we produce averaged sensitivity maps
for the "active" stars and the "inactive" stars, for the sake of comparison. We
quantify the extent to which signal-to-noise is degraded for transit detection,
when comparing an active star to an inactive star of the same temperature and
apparent brightness. We aim for these sensitivity maps to be useful to the
exoplanet community in future M dwarf occurrence rate studies.
