Variability induced motion in Kepler data

TL;DR

This study analyzes Kepler data to detect variability induced motion (VIM), revealing correlated astrometric and photometric shifts in over 129,000 stars, and provides a catalog for further astrophysical investigations.

Contribution

It presents the first comprehensive catalog of VIM detections in Kepler data, identifying correlated signals and potential contamination sources.

Findings

VIM detected in 129,525 stars across Kepler data

4440 Kepler objects of interest show VIM at least once

VIM signals associated with variable stars and superflares

Abstract

Variability induced motion (VIM) is an observable effect in simultaneous astrometric and photometric measurements caused by brightness variation in one of the components of a double source or blended image, which manifests itself as a strongly correlated shift of the optical photocenter. We have processed the entire collection of the Kepler long-cadence light curve data looking for correlated signals in astrometry and photometry on the time basis of a quarter year. Limiting the VIM correlation coefficient to 0.3, VIM events are detected for 129,525 Kepler stars at least in one quarter. Of 7305 Kepler objects of interest (KOI), 4440 are detected as VIM at least once. Known variable stars and resolved double stars have elevated rates of VIM detection. Confident VIM occurrences are found for stars with suggested superflare events, indicating possible signal contamination. We present a complete catalog of all quarterly VIM detections. This catalog should be checked for such astrophysically significant events as transits of exoplanets, new eclipsing stars, and superflares of solar-type stars.