Limits on the Abundance of Galactic Planets From 5 Years of PLANET Observations

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Abstract
We search for signatures of planets in 43 intensively monitored microlensing events that were observed between 1995 and 1999. Planets would be expected to cause a short-duration (~1 day) deviation on the smooth, symmetric light curve produced by a single lens. We find no such anomalies and infer that less than one-third of the ~0.3 M☉ stars that typically comprise the lens population have Jupiter mass companions with semimajor axes in the range of 1.5 AU < a < 4 AU. Since orbital periods of planets at these radii are 3-15 yr, the outer portion of this region is currently difficult to probe with any other technique.