In this paper I show how to calculate the effect of a nearby Pearl vortex or
antivortex upon the critical current Ic(B) when a perpendicular magnetic
induction B is applied to a planar Josephson junction in a long, thin
superconducting strip of width W much less than the Pearl length Λ=2λ2/d, where λ is the London penetration depth and d is the
thickness (d<λ). The theoretical results provide a qualitative
explanation of unusual features recently observed experimentally by Golod {\it
et al.}\cite{Golod10} in a device with a similar geometry.Comment: 8 pages, 11 figure