Study of Planetary Systems around Giant Stars

TL;DR

This paper reviews the current state of exoplanet detection around giant stars, highlighting the differences from main-sequence stars and presenting ongoing RV search efforts to understand planet formation and evolution around intermediate-mass, post-main-sequence stars.

Contribution

It provides a comprehensive overview of exoplanets around giant stars and reports on a radial velocity survey targeting southern hemisphere giants to explore planetary formation and evolution.

Findings

Approximately 30 planets found orbiting giant stars.

Detection fraction around giant stars appears higher than for solar-type stars.

Ongoing RV survey aims to understand planet-star interactions post-MS.

Abstract

More than 450 exoplanets have currently been detected, most of them by the radial velocity (RV) technique. While the majority of exoplanets have been found around main-sequence (MS) FGK stars (M 1.5M*), only a small fraction (- 10%) have been discovered orbiting post- MS stars. However, such stars are known to host exoplanets and the detection fraction appears to be larger than for solar-type dwarfs. To date - 30 planets have been found orbiting giant stars which have revealed interesting properties that contrast with the results found for solar-type stars. We are carrying out a RV search for planets around giant stars in the southern hemisphere in order to study different formation scenarios for planets around intermediate-mass stars and the effect of the post-MS evolution of the host stars on the orbits of close-in planets (a 0.6 AU).