Exoplanet in the triple star system as the probable source of effective cyclotron emission

Interaction of exoplanet with a host star in the triple star system is considered. Besides reconnection of the stellar and planetary magnetic fields (if they exist), the specific interaction of exoplanet with three stars leads to increased impact on the planetary environment and the host star astrosphere. Encounters with different kinds of corotation interaction regions from the stellar winds of the distant stars in the triple system affect the host-star's astrosphere. Just out of the astrosphere's boundary, dynamo can act for the rapidly rotating magnetic host star, because corotation, transferred along open field lines, brakes down there with possible generation of magnetic field. When several stars exist in the system, the effect of their CMEs and flare activities can summarize. Rotational synchronization between the host star and close-in exoplanet can intensify the coronal activity of the star. All these effects could lead to possible increase of magnetic field at the boundary of the host star astrosphere and inside it, which, consequently, will result in the enhanced cyclotron radio emission from such systems. •Triple star system with exoplanet can be a source of cyclotron radio emission.•Specific features of interaction between the distant stars' winds are CIRs and MIRs.•At the boundary of rapidly rotating magnetic star astrosphere the dynamo can act.