Kepler Bonus: Aperture Photometry Light Curves of EXBA Sources

TL;DR

This paper presents a new dataset of light curves for over 9,000 sources observed in Kepler's background regions using custom apertures, enabling diverse time domain astrophysics studies.

Contribution

The authors produce and release light curves for sources in Kepler's background regions using PRF-based aperture photometry, along with a Python library for similar analyses.

Findings

Discovered an exoplanet candidate around Gaia EDR3 2077240046296834304.

Cataloged 69 eclipsing binaries from the new light curves.

Demonstrated the utility of background region data for astrophysical research.

Abstract

NASA's Kepler mission observed background regions across its field of view for more than three consecutive years using custom designed super apertures (EXBA masks). Since these apertures were designed to capture a region of the sky rather than single targets, the Kepler Science Data Processing pipeline produced Target Pixel Files, but did not produce light curves for the sources within these background regions. In this work we produce light curves for $9,327$ sources observed in the EXBA masks. These light curves are generated using aperture photometry estimated from the instrument's Pixel Response Function (PRF) profile computed from Kepler's full-frame images. The PRF models enable the creation of apertures that follow the characteristic shapes of the PSF in the image and the computation of flux completeness and contamination metrics. The light curves are available at MAST as a High Level Science Product (kbonus-apexba). Alongside this dataset, we present kepler-apertures, a Python library to compute PRF models and use them to perform aperture photometry on Kepler-like data. Using light curves from the EXBA masks we found an exoplanet candidate around Gaia EDR3 2077240046296834304 consistent with a large planet companion with a $0.81 R_J$ radius. Additionally, we report a catalog of 69 eclipsing binaries. We encourage the community to exploit this new dataset to perform in depth time domain analysis, such as eclipsing binaries demographic and others.