(where r i is the ion distance from the Sun of mass M, m' is the atom weight, V ion is in volts, k is the gravitational constant). Then when the gas becomes ionized, electromagnetic forces come into effect, of which the most important is the magnetic force which is usually greater than the gravitational force which gives rise to a magnetic repulsion from the Sun. In other words, a neutral gas falling from infinity toward the Sun is stopped at a distance r i where it will accumulate, and perhaps condense into planets.