Radial Velocity search for substellar companions to sdB stars

TL;DR

This study uses radial velocity measurements to search for substellar companions around bright sdB stars, aiming to understand their role in stellar evolution and hot subdwarf formation.

Contribution

It introduces a new observational approach to detect substellar companions to sdB stars and tests their influence on stellar evolution.

Findings

Initial results show no confirmed substellar companions yet.

Supports the hypothesis that some hot subdwarfs may have survived planetary interactions.

Provides constraints on the frequency of planetary companions around sdB stars.

Abstract

After the discovery of a substellar companion to the hot subdwarf HD 149382, we have started a radial velocity search for similar objects around other bright sdB stars using the Anglo-Australian Telescope. Our aim is to test the hypothesis that close substellar companions can significantly affect the post-main sequence evolution of solar-type stars. It has previously been proposed that binary interactions in this scenario could lead to the formation of hot subdwarfs. The detection of such objects will provide strong evidence that Jupiter-mass planets can survive the interaction with a solar-type star as it evolves up the Red Giant Branch. We present the first results of our search here.