The Kepler-SEP Mission: Harvesting the South Ecliptic Pole large-amplitude variables with Kepler

TL;DR

The Kepler-SEP Mission aims to observe large-amplitude variable stars at the South Ecliptic Pole with high cadence, leveraging existing and upcoming missions to enhance understanding of stellar pulsation physics and improve astrophysical tools.

Contribution

This paper proposes a new mission concept to repurpose Kepler for long-term, high-cadence observations of variable stars at the South Ecliptic Pole, integrating data from multiple missions.

Findings

Feasibility of Kepler-SEP with minimal reprogramming.

Synergies with Gaia, TESS, and ground surveys enhance scientific return.

Potential to improve stellar pulsation and evolution models.

Abstract

As a response to the white paper call, we propose to turn Kepler to the South Ecliptic Pole (SEP) and observe thousands of large amplitude variables for years with high cadence in the frame of the Kepler-SEP Mission. The degraded pointing stability will still allow observing these stars with reasonable (probably better than mmag) accuracy. Long-term continuous monitoring already proved to be extremely helpful to investigate several areas of stellar astrophysics. Space-based missions opened a new window to the dynamics of pulsation in several class of pulsating variable stars and facilitated detailed studies of eclipsing binaries. The main aim of this mission is to better understand the fascinating dynamics behind various stellar pulsational phenomena (resonances, mode coupling, chaos, mode selection) and interior physics (turbulent convection, opacities). This will also improve the applicability of these astrophysical tools for distance measurements, population and stellar evolution studies. We investigated the pragmatic details of such a mission and found a number of advantages: minimal reprogramming of the flight software, a favorable field of view, access to both galactic and LMC objects. However, the main advantage of the SEP field comes from the large sample of well classified targets, mainly through OGLE. Synergies and significant overlap (spatial, temporal and in brightness) with both ground- (OGLE, LSST) and space-based missions (GAIA, TESS) will greatly enhance the scientific value of the Kepler-SEP mission. GAIA will allow full characterization of the distance indicators. TESS will continuously monitor this field for at least one year, and together with the proposed mission provide long time series that cannot be obtained by other means. If Kepler-SEP program is successful, there is a possibility to place one of the so-called LSST "deep-drilling" fields in this region.