Higher order Compton-Getting anisotropies.

The Compton-Getting effect relates the distribution function of a particle population in a given frame of reference to that in another frame, moving at constant velocity V relative to the first. A study is made of the effects that arise when, contrary to previous assumptions, second-order terms in (V/v), where v is the particle velocity, are retained, and when the given distribution function is not isotropic. The importance of the extra terms is then examined in the specific case of low-energy solar protons in interplanetary space.