Summary: THE FORMATION AND EVOLUTION OF THE
PERSEID METEOROID STREAM
Nathan W. Harris 1;2
1 Astrophysics Research Group, School of Electrical Engineering,
Electronics & Physics, Liverpool John Moores University, Byrom Street,
Liverpool, L3 3AF, UK.
Abstract. The orbital evolution of two modelled `Perseid' meteoroid
streams is investigated using direct numerical integration techniques. We
conclude that, in the absence of significant meteoroid velocity determina­
tion errors, the observed meteoroid orbital semi­major axis distribution is
a direct consequence of the cometary ejection process and not due to sub­
sequent orbital evolution. A high ejection­velocity (¸ 0:6 km s \Gamma1 ) model
stream succeeds in reproducing the observations. Conclusions are made
concerning how the orbital stability of Earth­orbit­intersecting Perseid
meteoroids varies with initial orbital semi­major axis.
1. Introduction
A simple model has been developed to represent the formation of the Perseid
meteoroid stream by considering the way in which both the velocity of the me­
teoroids emitted from the surface of the parent cometary nucleus (109P/Swift­
Tuttle) and the number ejected per unit time vary as a function of heliocentric

Source: Armagh Observatory

Collections: Physics