From Jupiter-family to Encke-like orbits

The rôle of non-gravitational forces and resonances

¹ Astronomical Institute of SAV, Bratislava, Slovak Republic
² Istituto di Astrofisica Spaziale e Fisica Cosmica, Roma, Italy

Corresponding author: G. B. Valsecchi, giovanni@rm.iasf.cnr.it

Received: 16 July 2003
Accepted: 12 March 2004

Abstract

We investigate numerically the transfer routes from Jupiter-family towards Encke-like cometary orbits, including in the model all the planets as well as non-gravitational forces. The numerical integrations are started from orbital elements similar to those of 2P/Encke, changing the perihelion distance q, to obtain starting orbits in the Jupiter family, and the non-gravitational parameter A₂. The results show that some of the model orbits reach the Encke-like stage within a reasonable time, comparable to a typical active cometary lifetime; along the way, at the crossing of mean motion resonances with Jupiter, temporary captures in resonance may occur. Thus, resonances and non-gravitational forces appear to be key factors in the transfer of orbits from the Jupiter family to the Encke region.