sentences:  Examples of the bicenter problem include a planet moving around two slowly moving stars, or an electron moving in the electric field of two positively charged nuclei, such as the first ion of the hydrogen molecule H2, namely the hydrogen molecular ion or H2+.The strength of the two attractions need not be equal; thus, the two stars may have different masses or the nuclei two different charges.Let the fixed centers of attraction be located along the "x"-axis at ±"a".