  To extend LSST's coverage of the transient and variable sky down to minute
timescales, we propose that observations of the Deep Drilling Fields are
acquired in sequences of continuous exposures each lasting 2--4 hours. This
will allow LSST to resolve rapid stellar variability such as short-period
pulsations, exoplanet transits, ultracompact binary systems, and flare
morphologies, while still achieving the desired co-added depths for the
selected fields. The greater number of observations of each Deep Drilling Field
pushes these mini-surveys deep in terms of both sensitivity to low-amplitude
variability and co-added depth. Saving the individual 15-second exposures will
yield an effective Nyquist limit of $\approx0.031$ Hz (32 seconds). Resolved
short-period variability of targets in these fields will aid the interpretation
of sparse observations of a greater number of variables in the main survey. If
this cadence strategy conflicts with the science goals of individual Deep
Drilling Fields, at least a subset of the additional observations of each field
should be obtained continuously. This strategy should also be considered for
the proposed Galactic Plane mini survey, which will observe a greater number of
stellar variables and transients.
