A HET search for planets around evolved stars

TL;DR

This ongoing survey of about 1000 evolved GK-giant stars aims to detect planets using high-precision radial velocity measurements, contributing valuable data on planet formation and dynamics around evolved intermediate-mass stars.

Contribution

It is one of the few large-scale surveys targeting planets around evolved stars, providing new detections and candidates that inform theories of planet formation and evolution.

Findings

Discovery of a planetary-mass companion to HD 17092

Identification of multiple plausible planet candidates

Enhanced understanding of planetary system dynamics around evolved stars

Abstract

We present our ongoing survey of ~1000 GK-giants with the 9.2-m Hobby-Eberly Telescope in search for planets around evolved stars. The stars selected for this survey are brighter than 11 mag and are located in the section of the HR-diagram, which is approximately delimited by the main sequence, the instability strip, and the coronal dividing line. We use the High Resolution Spectrograph to obtain stellar spectra for radial velocity measurements with a 4-6 m/s precision. So far, the survey has discovered a planetary-mass companion to the K0-giant HD 17092, and it has produced a number of plausible planet candidates around other stars. Together with other similar efforts, our program provides information on planet formation around intermediate mass main sequence-progenitors and it will create the experimental basis with which to study dynamics of planetary systems around evolving stars.