  The eccentricity distribution of exoplanets is known from radial velocity
surveys to be divergent from circular orbits beyond 0.1 AU. This is
particularly the case for large planets where the radial velocity technique is
most sensitive. The eccentricity of planetary orbits can have a large effect on
the transit probability and subsequently the planet yield of transit surveys.
The Kepler mission is the first transit survey that probes deep enough into
period-space to allow this effect to be seen via the variation in transit
durations. We use the Kepler planet candidates to show that the eccentricity
distribution is consistent with that found from radial velocity surveys to a
high degree of confidence. We further show that the mean eccentricity of the
Kepler candidates decreases with decreasing planet size indicating that smaller
planets are preferentially found in low-eccentricity orbits.
