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 such 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 total variation (length) of the residual timeseries with regard to the perbin 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.
 Publication:

Publications of the Astronomical Society of the Pacific
 Pub Date:
 June 2019
 DOI:
 10.1088/15383873/ab0f41
 arXiv:
 arXiv:1902.08182
 Bibcode:
 2019PASP..131f8001P
 Keywords:

 Astrophysics  Instrumentation and Methods for Astrophysics;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 9 pages, 2 figures