The SOPHIE search for northern extrasolar planets. II. A multi-planet system around HD9446

TL;DR

This paper reports the discovery of a multi-planet system around HD9446 using radial velocity measurements, revealing two planets with different masses and orbital characteristics, contributing to understanding planetary system architectures.

Contribution

First detection of multiple planets around HD9446 using SOPHIE spectrograph, demonstrating the system's hierarchical structure with a massive outer planet and a lighter inner planet.

Findings

HD9446b has a 30-day period and 0.7 M_Jup mass.

HD9446c has a 193-day period and 1.8 M_Jup mass.

The system exhibits a hierarchical planetary arrangement.

Abstract

We report the discovery of a planetary system around HD9446, performed from radial velocity measurements secured with the spectrograph SOPHIE at the 193-cm telescope of the Haute-Provence Observatory during more than two years. At least two planets orbit this G5V, active star: HD9446b has a minimum mass of 0.7 M_Jup and a slightly eccentric orbit with a period of 30 days, whereas HD9446c has a minimum mass of 1.8 M_Jup and a circular orbit with a period of 193 days. As for most of the known multi-planet systems, the HD9446-system presents a hierarchical disposition, with a massive outer planet and a lighter inner planet.