Coma morphology and dust-emission pattern of periodic Comet Halley. IV - Spin vector refinement and map of discrete dust sources for 1910
The concept of continuous ejection of dust from discrete emission sources located on the sunlit hemisphere of a rotating comet nucleus, described in the previous papers of this series, has been applied to 55 features on 34 digitally processed plates of comet Halley from the period 1910 May 5 - June 6 and to the reported projected lengths of six antisunward jets observed between 1910 May 14 and June 6. The authors present a first map of the comet's nucleus with 13 discrete sources of dust, of which only two can be modeled as point-like regions. The remaining 11 sources are extending over the surface in at least one dimension. Their distribution and characteristics are discussed in detail.