  Hot subdwarf stars are mostly stripped red giants that can exhibit
photometric variations due to stellar pulsations, eclipses, the reflection
effect, ellipsoidal modulation, and Doppler beaming. Detailed studies of their
light curves help constrain stellar parameters through asteroseismological
analyses or binary light curve modeling and generally improve our capacity to
draw a statistically meaningful picture of this enigmatic stage of stellar
evolution. From an analysis of Gaia DR2 flux errors, we have identified around
1200 candidate hot subdwarfs with inflated flux errors for their magnitudes - a
strong indicator of photometric variability. As a pilot study, we obtained
2-min cadence TESS Cycle 2 observations of 187 candidate hot subdwarfs with
anomalous Gaia flux errors. More than 90% of our targets show significant
photometric variations in their TESS light curves. Many of the new systems
found are cataclysmic variables, but we report the discovery of several new
variable hot subdwarfs, including HW Vir binaries, reflection effect systems,
pulsating sdBVs stars, and ellipsoidally modulated systems. We determine
atmospheric parameters for select systems using follow-up spectroscopy from the
3-m Shane telescope. Finally, we present a Fourier diagnostic plot for
classifying binary light curves using the relative amplitudes and phases of
their fundamental and harmonic signals in their periodograms. This plot makes
it possible to identify certain types of variables efficiently, without
directly investigating their light curves, and may assist in the rapid
classification of systems observed in large photometric surveys.
