| Abstract: | If the angle ϵ between the radius vector and the axis of the comet tail is known one can determine the velocity component of the solar wind pointing into the direction of the radius vector. This paper describes a geometrical method to determine the orientation of cometary tails (it will be represented by l ). If n is the normal vector of the cometary orbit, ϱ is the geocentrical position vector of the cometary nuclei and ϱ * is the geocentrical direction vector towards the direction of an indicated arbitary point of the cometary tail (and the equality | ϱ |; = |; ϱ |;* holds) then by means of the factor k where k = nϱ/nϱ* the vector l = k ϱ * – ϱ can be calculated. The factor k is indefinite when nq* = o that means when the Earth passes through the orbit of the comet. At that time ϵ must be determined in other ways for example by means of dynamical methods or ϵ must be interpolated between two neighbouring observed data which are sufficiently near in time. A continuous ϵ-time function must be assumed. |
