Abstract:
A planet/comet-sun-Galaxy system is considered, under the assumption that the whole mass of the Galaxy is concentrated at its center, in order to find the limiting direct and retrograde orbits around the sun using King-Innanen's formula (King, 1962; Innanen, 1979), and to provide a boundary to the solar system. It is suggested that if the solar companion exists and has a mass in the 0.005-0.03 solar mass range and eccentricity of 0.7, it necessarily has a retrograde orbit. According to the present scenario, such a solar companion would belong to the comet belt hypothesized by Oort (1950), and could be taken to be a condensation of the solar material in the wide ring of the tenuous material of the solar nebula
