The Trojan-like Colors of Low-perihelion Kuiper Belt Objects

Abstract

An important testable prediction of dynamical instability models for the early evolution of the solar system is that Jupiter Trojans share a source population with the Kuiper Belt. Concrete evidence of this prediction remains elusive, as Kuiper Belt objects (KBOs) and Jupiter Trojans appear to have different surface compositions. We address the long-standing question of Trojan origin by finding a dynamical subpopulation in the Kuiper Belt with Trojan-like colors. Combining existing photometric data with our own surveys on Keck I and Palomar P200, we find that the low-perihelion ( q 30 au) component of the Kuiper Belt has colors that bifurcate similarly to the Jupiter Trojans, unlike Centaurs ( a 0.6 KBOs) contribute more to the low-perihelion KBO population than to Centaurs, resulting in their different colors.

Keywords

• Kuiper belt
• Photometry
• Solar system evolution
• Centaur group
• Jupiter trojans