Asymptotic beam patterns of 4U 0115+63 as seen by the distant observer plotted over the angle θ_obs between the first magnetic pole and the line of sight for the observations A (before maximum), B (maximum), C (after maximum), and E (end of decay). Errors are propagated statistical errors of the pulse profiles. Only the minus solution is shown, which is the physically reasonable solution (see Sect. 3.1.1). The plus solution can be obtained by transforming θ_obs to π − θ_obs.