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Planets with several Earth masses and a few day orbital periods have beendiscovered through radial velocity and transit surveys. Regardless of theirformation mechanism, a key evolution issue is the efficiency of their retentionnear their host stars. If these planets attained their present-day orbitsduring or shortly after the T Tauri phase of their host stars, a large fractionwould have encountered intense stellar magnetic field. Since these planets havea higher conductivity than the atmosphere of their stars, the magnetic fluxtube connecting the planet and host star would slip though the envelope of thestar faster than across the planet. The induced electro-motive force across theplanet's diameter leads to a potential drop which propagates along a flux tubeaway from the planet with an Alfven speed. The foot of the flux tube sweepsacross the stellar surface and the potential drop drives a DC current analogousto that proposed for the Io-Jupiter electrodynamic interaction. The ohmicdissipation of this current produces potentially observable hot spots in thestar envelope. The current heats the planet and leads to a Lorrentz torquewhich drives the planet's orbit to evolve toward circularization andsynchronization with the star's spin. The net effect is the damping of theplanet's orbital eccentricity. Around slowly (rapidly) spinning stars, thisprocess also causes rocky planets with periods less than a few days to undergoorbital decay (expansion/stagnation) within a few Myr. In principle, thiseffect can determine the retention efficiency of short-period hot Earths. Wealso estimate the ohmic dissipation in these planets and show that it can leadto severe structure evolution and potential loss of volatile material. However,these effects may be significantly weakened by the reconnection of the inducedfield [Slightly shortened abstract].

Interaction of Close-in Planets with the Magnetosphere of their Host Stars. II. Super-Earths as Unipolar Inductors and their Orbital Evolution