HD45364, a pair of planets in a 3:2 mean motion resonance

TL;DR

This paper reports the discovery of a unique two-planet system around HD45364 in a 3:2 mean motion resonance, providing insights into planetary formation and migration.

Contribution

First observation of a 3:2 resonant exoplanet system, offering new constraints on planetary formation theories.

Findings

Two planets with specific masses and orbits confirmed.

System remains stable over 5 billion years.

First known exoplanet system in 3:2 resonance.

Abstract

Precise radial-velocity measurements with the HARPS spectrograph reveal the presence of two planets orbiting the solar-type star HD45364. The companion masses are 0.187 Mjup and 0.658 Mjup, with semi-major axes of 0.681 AU and 0.897 AU, and eccentricities of 0.168 and 0.097, respectively. A dynamical analysis of the system further shows a 3:2 mean motion resonance between the two planets, which prevents close encounters and ensures the stability of the system over 5 Gyr. This is the first time that such a resonant configuration has been observed for extra-solar planets, although there is an analogue in our Solar System formed by Neptune and Pluto. This singular planetary system may provide important constraints on planetary formation and migration scenarios.