Nine months of monitoring of a V777-Her pulsator with the Kepler spacecraft

TL;DR

This study reports nine months of continuous Kepler observations of the V777 Her pulsator KIC 8626021, revealing new pulsation modes and demonstrating mode stability, with implications for measuring period changes.

Contribution

It presents the first extended Kepler dataset for this pulsator, detecting new modes and analyzing mode stability for the first time.

Findings

Two new pulsation modes matching e2=2 sequence

Photometric stability of main modes confirmed

Potential to measure period changes over extended observation

Abstract

The V777 Her pulsator KIC 8626021 has been observed continuously by the Kepler space telescope for nine months. Two new independent pulsation modes are detected in the extended dataset, which both match the predicted sequence of \ell = 2 modes. We demonstrate the photometric stability of the main pulsation modes and discuss the prospect of measuring period changes within the context of the extended Kepler mission.