1992 年 85 巻 3 号 p. C57-C59
We studied a planet-magnetosphere interaction model for γ-ray bursts with the picture of a current circuit which consists of the magnetosphere and the surface of a neutron star. The motion of planets or comets in the magnetosphere works as the battery in the circuit system. The physical condition on the surface of the neutron star is important to make a closed current circuit inducing good conversion from the kinetic energy of a planet to that of the magnetosphere oscillation. An old and cooled neutron star with the temperature ≃ 10eV can prepare the condition for closing the current circuit in the surface of the neutron star. The planet-magnetosphere system is unstable to feedback instability related to the variability of the γ-ray bursts.