Photon Flux Perturbations of Kepler Light Curves

TL;DR

This paper proposes a novel method for detecting extrasolar moons by analyzing Kepler K2 light curves, identifying perturbations in transit timing that suggest moon presence, and testing against alternative explanations.

Contribution

It introduces a new approach to identify extrasolar moons through detailed light curve analysis and comparison with known phenomena, expanding exoplanet research methodologies.

Findings

Detected potential extrasolar moon signatures in Kepler data

Ruled out common false positives like star spots and multi-planet effects

Identified characteristic flux decreases linked to moon transits

Abstract

In this study, we expand the discussion of extrasolar planetary research by proposing a new approach to detecting extrasolar moons using Kepler (K2) light curves. We shaped this investigation by comparing transit light curve data of ~5000 main-sequence stars cataloged in the NASA Exoplanet Archive, the Radio Galaxy Zoo Exoplanet Explorers and the Exoplanet Follow Up Observing Program, which served as the repository to collect and analyze supplementary K2 data. By examining K2 light curves, various characteristics related to transits were modeled, which we then compared with confirmed extrasolar planets, variable stars such as eclipsing binaries and noise or gaps in the data. For illustration, perturbations in the timing of two separate transits for 2MASS J08251369+1425306 (Rs ~ 0.346) produced two characteristic decreases in the photon flux followed by two increases, inferring the presence of an extrasolar planet (Rp ~ 0.0129) and its companion, an extrasolar moon (Rm ~ 0.0048). To test our hypothesis, we scrutinized various competing assumptions to resolve the source of the duo photon flux, namely the Rossiter McLaughlin effect, limb darkening, a multiplanet system or a planet occulting one or more sunspots on the surface of the star. However, we uncovered no analogous light curve in K2 to fit the competing hypotheses and account for the proposed extrasolar companion.