Abstract
We study one-dimensional envelope solitons in gyrotropic media (plasmas, condensed matter, etc.). The basic equations are reduced to a system of two coupled nonlinear Schrödinger equations which, depending on parameters, describe stationary or radiating solitons. A transition from one case to the other is investigated analytically and an asymptotic solution describing soliton radiation is obtained. The soliton damping rate due to the radiation is calculated.