Extracting Periodic Transit Signals from Noisy Light Curves Using Fourier Series

Research output: Contribution to journalJournal articleResearchpeer-review

We present a simple and powerful method for extracting transit signals associated with a known transiting planet from noisy light curves. Assuming the orbital period of the planet is known and the signal is periodic, we illustrate that systematic noise can be removed in Fourier space at all frequencies by only using data within a fixed time frame with a width equal to an integer number of orbital periods. This results in a reconstruction of the full transit signal, which on average is unbiased despite no prior knowledge of either the noise or the transit signal itself being used in the analysis. The method therefore has clear advantages over standard phase folding, which normally requires external input such as nearby stars or noise models for removing systematic components. In addition, we can extract the full orbital transit signal (360°) simultaneously, and Kepler-like data can be analyzed in just a few seconds. We illustrate the performance of our method by applying it to a dataset composed of light curves from Kepler with a fake injected signal emulating a planet with rings. For extracting periodic transit signals, our presented method is in general the optimal and least biased estimator and could therefore lead the way toward the first detections of, e.g., planet rings and exo-trojan asteroids.

Original languageEnglish
Article number65
JournalAstrophysical Journal
Volume807
Issue number1
ISSN0004-637X
DOIs
Publication statusPublished - 1 Jul 2015
Externally publishedYes

    Research areas

  • methods: data analysis, Planetary systems

ID: 236271920