The Quasiperiodic Automated Transit Search Algorithm

TL;DR

The paper introduces QATS, an algorithm for detecting transiting exoplanets that allows for variable transit intervals, effectively identifying planets with transit timing variations in space-based photometric data.

Contribution

QATS is a novel algorithm that relaxes the strict periodicity assumption, enabling detection of planets with TTVs without significant loss of detection significance.

Findings

QATS can detect planets with significant TTVs without smearing.

The algorithm has comparable runtime complexity to traditional methods.

QATS is suitable for space-based, high-cadence photometric data.

Abstract

We present a new algorithm for detecting transiting extrasolar planets in time-series photometry. The Quasiperiodic Automated Transit Search (QATS) algorithm relaxes the usual assumption of strictly periodic transits by permitting a variable, but bounded, interval between successive transits. We show that this method is capable of detecting transiting planets with significant transit timing variations (TTVs) without any loss of significance -- "smearing" -- as would be incurred with traditional algorithms; however, this is at the cost of an slightly-increased stochastic background. The approximate times of transit are standard products of the QATS search. Despite the increased flexibility, we show that QATS has a run-time complexity that is comparable to traditional search codes and is comparably easy to implement. QATS is applicable to data having a nearly uninterrupted, uniform cadence and is therefore well-suited to the modern class of space-based transit searches (e.g., Kepler, CoRoT). Applications of QATS include transiting planets in dynamically active multi-planet systems and transiting planets in stellar binary systems.