100-year DASCH Light Curves of Kepler Planet-Candidate Host Stars

TL;DR

This study provides century-long light curves for Kepler planet-hosting stars using DASCH data, finding no significant variability, including in systems with hot Jupiters, thus offering long-term stability insights.

Contribution

First to analyze 100-year light curves of Kepler planet-host stars using DASCH, revealing their photometric stability over a century.

Findings

No significant variability detected at 3-sigma level.

Hot Jupiter systems show no enhanced flares or variability.

Photometric uncertainty is approximately 0.1-0.15 mag.

Abstract

We present 100 year light curves of Kepler planet-candidate host stars from the Digital Access to a Sky Century at Harvard (DASCH) project. 261 out of 997 host stars have at least 10 good measurements on DASCH scans of the Harvard plates. 109 of them have at least 100 good measurements, including 70% (73 out of 104) of all host stars with g<=13 mag, and 44% (100 out of 228) of all host stars with g<=14 mag. Our typical photometric uncertainty is ~0.1-0.15 mag. No variation is found at 3-sigma level for these host stars, including 21 confirmed or candidate hot Jupiter systems which might be expected to show enhanced flares from magnetic interactions between dwarf primaries and their close and relatively massive planet companions.