The Kep-Cont Mission: Continuing the observation of high-amplitude variable stars in the Kepler field of view

TL;DR

The Kep-Cont Mission aims to continue high-cadence observations of large amplitude variable stars in the Kepler field, enabling detailed studies of stellar pulsations, period jitter, and dynamical effects over an extended, homogeneous dataset despite degraded pointing stability.

Contribution

This paper proposes a continuation of Kepler observations focusing on variable stars, highlighting the scientific benefits and pragmatic implementation details of the Kep-Cont Mission.

Findings

Allows study of nonradial modes in RR Lyrae stars

Provides long-term data for Blazhko effect analysis

Enables detection of dynamical effects like apsidal motion

Abstract

As a response to the Kepler white paper call, we propose to keep Kepler pointing to its current field of view and continue observing thousands of large amplitude variables (Cepheid, RR Lyrae and delta Scuti stars among others) with high cadence in the Kep-Cont Mission. The degraded pointing stability will still allow observation of these stars with reasonable (better than millimag) precision. The Kep-Cont mission will allow studying the nonradial modes in Blazhko-modulated and first overtone RR Lyrae stars and will give a better view on the period jitter of the only Kepler Cepheid in the field. With continued continuous observation of the Kepler RR Lyrae sample we may get closer to the origin of the century-old Blazhko problem. Longer time-span may also uncover new dynamical effects like apsidal motion in eclipsing binaries. A continued mission will have the advantage of providing unprecedented, many-years-long homogeneous and continuous photometric data of the same targets. We investigate the pragmatic details of such a mission and find a number of advantages, especially the minimal need of reprogramming of the flight software. Another undeniable advantage of the current field of view is the completed, ongoing and planned ground-based follow-up observations and allocated telescope times focusing on the current field. We emphasize that while we propose this continuation as an independent mission, we can easily share slots with e.g. planetary mission with a strong belief that both (or more) communities can still benefit from Kepler's current capabilities.