Massive remnant of evolved cometary dust trail detected in the orbit of Halley-type comet 55P/Tempel-Tuttle

There is a subpopulation of Leonid meteoroid stream particles that appear to form a region of enhanced numbers density along the path of the stream. This structure has been detected in the vicinity of the parent comet, and its variation from one apparition to the next has been traced. A significant amount of known comet 55P/Tempel-Tuttle debris is in this component, called a "filament," which has dimensions exceeding by an order of magnitude that expected for a cometary dust trail. As filament particles are of a size comparable to those found in trails, the emission ages of the particles comprising the filament must be intermediate between the age of the current trail particles (which have not been observed) and the age of the background particles comprising the annual showers. The most likely explanation for this structure is planetary perturbations acting differently on the comet and large particles while at different mean anomalies relative to each other.