SUPER-ECCENTRIC MIGRATING JUPITERS

Abstract

An important class of formation theories for hot Jupiters involves the\nexcitation of extreme orbital eccentricity (e=0.99 or even larger) followed by\ntidal dissipation at periastron passage that eventually circularizes the\nplanetary orbit at a period less than 10 days. In a steady state, this\nmechanism requires the existence of a significant population of super-eccentric\n(e>0.9) migrating Jupiters with long orbital periods and periastron distances\nof only a few stellar radii. For these super-eccentric planets, the periastron\nis fixed due to conservation of orbital angular momentum and the energy\ndissipated per orbit is constant, implying that the rate of change in\nsemi-major axis a is \\dot a \\propto a^0.5 and consequently the number\ndistribution satisfies dN/dlog a\\propto a^0.5. If this formation process\nproduces most hot Jupiters, Kepler should detect several super-eccentric\nmigrating progenitors of hot Jupiters, allowing for a test of high-eccentricity\nmigration scenarios.\n