Sounding stellar cycles with Kepler - preliminary results from ground-based chromospheric activity measurements

TL;DR

This study combines Kepler asteroseismic data with ground-based chromospheric activity measurements to investigate stellar cycles, aiming to enhance understanding of stellar magnetic activity and improve stellar evolution models.

Contribution

It introduces a combined approach of space-based asteroseismology and ground-based chromospheric monitoring to study stellar cycles and their relation to stellar parameters.

Findings

Initial chromospheric activity measurements obtained

Ground-based data will guide Kepler target selection

Potential to correlate activity with stellar age and rotation

Abstract

Due to its unique long-term coverage and high photometric precision, observations from the Kepler asteroseismic investigation will provide us with the possibility to sound stellar cycles in a number of solar-type stars with asteroseismology. By comparing these measurements with conventional ground-based chromospheric activity measurements we might be able to increase our understanding of the relation between the chromospheric changes and the changes in the eigenmodes. In parallel with the Kepler observations we have therefore started a programme at the Nordic Optical Telescope to observe and monitor chromospheric activity in the stars that are most likely to be selected for observations for the whole satellite mission. The ground-based observations presented here can be used both to guide the selection of the special Kepler targets and as the first step in a monitoring programme for stellar cycles. Also, the chromospheric activity measurements obtained from the ground-based observations can be compared with stellar parameters such as ages and rotation in order to improve stellar evolution models.