The Pan-Pacific Planet Search. IV. Two super-Jupiters in a 3:5 resonance orbiting the giant star HD33844

TL;DR

This paper reports the discovery of two giant planets orbiting the giant star HD 33844, which are likely in a 3:5 mean-motion resonance, based on radial velocity data and dynamical stability analysis.

Contribution

First detection of two super-Jupiters in a 3:5 resonance around a giant star using radial velocity measurements and dynamical simulations.

Findings

Two giant planets with nearly circular orbits discovered around HD 33844.

Planets are in a stable 3:5 mean-motion resonance.

Planets have minimum masses of approximately 1.8-2.0 Jupiter masses.

Abstract

We report the discovery of two giant planets orbiting the K giant HD 33844 based on radial velocity data from three independent campaigns. The planets move on nearly circular orbits with semimajor axes $a_b=1.60\pm$0.02 AU and $a_c=2.24\pm$0.05 AU, and have minimum masses (m sin $i$) of $M_b=1.96\pm$0.12 Mjup and $M_c=1.76\pm$0.18 Mjup. Detailed N-body dynamical simulations show that the two planets remain on stable orbits for more than $10^6$ years for low eccentricities, and are most likely trapped in a mutual 3:5 mean-motion resonance.