A search for planetary eclipses of white dwarfs in the Pan-STARRS1   medium-deep fields
  We present a search for eclipses of $\sim$1700 white dwarfs in the Pan-STARRS1 medium-deep fields. Candidate eclipse events are selected by identifying low outliers in over 4.3 million light curve measurements. We find no short-duration eclipses consistent with being caused by a planetary size companion. This large dataset enables us to place strong constraints on the close-in planet occurrence rates around white dwarfs for planets as small as 2 R$_\oplus$. Our results indicate that gas giant planets orbiting just outside the Roche limit are rare, occurring around less than 0.5% of white dwarfs. Habitable-zone super-Earths and hot super-Earths are less abundant than similar classes of planets around main-sequence stars. These constraints give important insight into the ultimate fate of the large population of exoplanets orbiting main sequence stars. 
B. J. Fulton, J. L. Tonry, H. Flewelling, W. S. Burgett, K. C.   Chambers, K. W. Hodapp, M. E. Huber, N. Kaiser, R. J. Wains...
astro-ph.EP