Timing by Stellar Pulsations as an Exoplanet Discovery Method

TL;DR

This paper discusses using stellar pulsation timing as a method to detect exoplanets, especially around hot pulsating stars, by observing periodic shifts in pulsation arrival times caused by gravitational tugs.

Contribution

It introduces a novel exoplanet detection technique based on pulsation timing, applicable to various pulsating stars, and discusses its sensitivity and potential for new discoveries.

Findings

Effective for detecting substellar companions around hot pulsating stars

External gravitational influences cause measurable timing variations

Method is increasingly successful with long-term photometric data

Abstract

The stable oscillations of pulsating stars can serve as accurate timepieces, which may be monitored for the influence of exoplanets. An external companion gravitationally tugs the host star, causing periodic changes in pulsation arrival times. This method is most sensitive to detecting substellar companions around the hottest pulsating stars, especially compact remnants like white dwarfs and hot subdwarfs, as well as delta Scuti variables (A stars). However, it is applicable to any pulsating star with sufficiently stable oscillations. Care must be taken to ensure that the changes in pulsation arrival times are not caused by intrinsic stellar variability; an external, light-travel-time effect from an exoplanet identically affects all pulsation modes. With more long-baseline photometric campaigns coming online, this method is yielding new detections of substellar companions.