A 4-Planet System Orbiting the K0V Star HD 141399

TL;DR

This paper reports the discovery of a four-planet system orbiting star HD 141399 using precision radial velocity measurements, revealing insights into planetary system architecture and evolution.

Contribution

First detailed characterization of a four-planet system around HD 141399 using long-term RV data, including orbital parameters and potential evolutionary history.

Findings

Four planets with periods of 94, 202, 1070, and 3717 days identified.

Inner two planets are near a 2:1 resonance, indicating possible past dissipative evolution.

Outer planet is a Jupiter-like companion with low eccentricity.

Abstract

We present precision radial velocity (RV) data sets from Keck-HIRES and from Lick Observatory's new Automated Planet Finder Telescope and Levy Spectrometer on Mt. Hamilton that reveal a multiple-planet system orbiting the nearby, slightly evolved, K-type star HD 141399. Our 91 observations over 10.5 years suggest the presence of four planets with orbital periods of 94.35, 202.08, 1070.35, and 3717.35 days and minimum masses of 0.46, 1.36, 1.22, and 0.69 Jupiter masses respectively. The orbital eccentricities of the three inner planets are small, and the phase curves are well sampled. The inner two planets lie just outside the 2:1 resonance, suggesting that the system may have experienced dissipative evolution during the protoplanetary disk phase. The fourth companion is a Jupiter-like planet with a Jupiter-like orbital period. Its orbital eccentricity is consistent with zero, but more data will be required for an accurate eccentricity determination.