Finding the Needle in a Haystack: Detrending Photometric Timeseries Data of Strictly Periodic Astrophysical Objects

Abstract

Light curves of astrophysical objects frequently contain strictly periodic signals. In those cases we can use that property to aid the detrending algorithm to fully disentangle an unknown periodic signal and an unknown baseline signal with no power at that period. The periodic signal is modeled as a discrete probability distribution function (pdf), while the baseline signal is modeled as a residual timeseries. Those two components are disentangled by minimizing the length of the residual timeseries w.r.t. the per-bin pdf fluxes. We demonstrate the use of the algorithm on a synthetic case, on the eclipsing binary KIC 3953981 and on the eccentric ellipsoidal variable KIC 3547874. We further discuss the parameters and the limitations of the algorithm and speculate on the two most common use cases: detrending the periodic signal of interest and measuring the dependence of instrumental response on controlled instrumental variables. A more sophisticated version of the algorithm is released as open source on github and available via pip.

9 pages, 2 figures; code available from https://github.com/aprsa/dips and via pip3

References in corpus (14)

• The Transiting Exoplanet Survey Satellite
• The K2 Mission: Characterization and Early results
• Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• A box-fitting algorithm in the search for periodic transits
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
• Kepler Eclipsing Binary Stars. I. Catalog and Principal Characterization of 1879 Eclipsing Binaries in the First Data Release
• Kepler Eclipsing Binary Stars. VII. The Catalog of Eclipsing Binaries Found in the Entire Kepler Data-Set
• A Class of Eccentric Binaries with Dynamic Tidal Distortions Discovered with Kepler
• Heartbeat Stars, Tidally Excited Oscillations, and Resonance Locking
• KIC 8164262: a Heartbeat Star Showing Tidally Induced Pulsations with Resonant Locking
• Robust, open-source removal of systematics in Kepler data
• Kepler's Dark Worlds: a Low Albedo for an Ensemble of Neptunian and Terran Exoplanets

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• The Eclipsing Binaries via Artificial Intelligence. II. Need for Speed in PHOEBE Forward Models
• The Beam Balance -- Measuring Binary Systems via Relativistic Beaming Signals from Stars and their Companions