  The detection of exoplanets through direct imaging has produced numerous new
positive identifications in recent years. The technique is biased towards
planets at wide separations due to the difficulty in removing the stellar
signature at small angular separations. Planets in eccentric orbits will thus
move in and out of the detectable region around a star as a function of time.
Here we use the known diversity of orbital eccentricities to determine the
range of orbits which may lie beneath the detection threshold of current
surveys. We quantify the percentage of the orbit which yields a detectable
signature as a function of semi-major axis, eccentricity, and orbital
inclination and estimate the fraction of planets which likely remain hidden by
the flux of the host star.
