The EXOTIME targets HS0702+6043 and HS0444+0458

TL;DR

This paper uses pulsation timing in subdwarf B stars to study their evolution and search for substellar companions, providing insights into stellar evolution and exoplanet survival through asteroseismology.

Contribution

It demonstrates the dual use of pulsation data for asteroseismology and exoplanet detection around sdB stars, highlighting the potential for discovering surviving planets.

Findings

Timing analysis can reveal substellar companions.

Pulsation data constrains stellar evolutionary models.

Method applicable to other pulsating stars.

Abstract

Pulsations in subdwarf B (sdB) stars are an important tool to constrain the evolutionary status of these evolved objects. Interestingly, the same data used for this asteroseismological approach can also be used to search for substellar companions around these objects by analyzing the timing of the pulsations by means of a so-called O-C diagram. Substellar objects around sdB stars are important for two different reasons: they are suspected to be able to influence the evolution of their host-star and they are an ideal test case to examine the properties of exoplanets which have survived the red giant expansion of their host stars.