Automated preparation of Kepler time series of planet hosts for asteroseismic analysis

TL;DR

This paper introduces the KASOC Filter, an automated method to preprocess Kepler data by removing planetary transits and instrumental noise, enabling more effective asteroseismic analysis of solar-like and red giant stars.

Contribution

The paper presents a novel automated preprocessing method, the KASOC Filter, tailored for Kepler data of planetary host stars to improve asteroseismic analysis accuracy.

Findings

Significantly cleaner photometric time series after filtering.

Effective removal of planetary transits and instrumental signals.

Applicable to a wide range of Kepler stars beyond planetary hosts.

Abstract

One of the tasks of the Kepler Asteroseismic Science Operations Center (KASOC) is to provide asteroseismic analyses on Kepler Objects of Interest (KOIs). However, asteroseismic analysis of planetary host stars presents some unique complications with respect to data preprocessing, compared to pure asteroseismic targets. If not accounted for, the presence of planetary transits in the photometric time series often greatly complicates or even hinders these asteroseismic analyses. This drives the need for specialised methods of preprocessing data to make them suitable for asteroseismic analysis. In this paper we present the KASOC Filter, which is used to automatically prepare data from the Kepler/K2 mission for asteroseismic analyses of solar-like planet host stars. The methods are very effective at removing unwanted signals of both instrumental and planetary origins and produce significantly cleaner photometric time series than the original data. The methods are automated and can therefore easily be applied to a large number of stars. The application of the filter is not restricted to planetary hosts, but can be applied to any solar-like or red giant stars observed by Kepler/K2.