Intensity Distribution in the Heads of Comets

Abstract

Abstract In optical wavelengths, the light emitted by comets consists of sunlight, reflected by dust, and the emission features of atoms and molecules. In his paper from 1957, L. Haser develops the mathematical framework to describe the density distribution of cometary comas. When comet scientists refer to the Haser model , they mostly point to the density distribution of parent and fragment molecules in the coma. However, in his paper, Haser (1957) presented the analytic solution over the line of sight (column density) and considers two particular observation configurations of a nonhomogeneous coma. This translation of the paper, originally in French, stays as close to the source as possible, including using the original figures. Minor typesetting corrections were introduced and are annotated in the text. The Haser model is foundational in cometary atmosphere science, but Haser’s paper was not widely read due to language barriers and a lack of digital availability. This translation is presented in an effort to make Haser’s work accessible to the wider community. We would like to thank Drs Emmanuel Jehin (Univ. Liège) and Kumar Venkataramani (Auburn Univ.) for critically reading this translation.