Influence of Solar Photogravitation on the Motion of Comet Hale-Bopp

On the basis of photogravitational theory, the influence of solar photogravitation on the motion of comet Hale-Bopp is discussed. It is shown that for plasma tail of comet Hale-Bopp there is only one collinear point L₃ and for a few of dust tail there can be two coplanar points L₆, L₇ and three collinear points L₂₁, L₂₂, L₃. The regions in which the coplanar points exist and the dust grain of comet Hale-Bopp can move are also obtained.