transit-least-squares

The Transit Least Squares (TLS) skill is an advanced analytical tool designed for astronomers, data scientists, and researchers working with exoplanetary transit data. Unlike the standard Lomb-Scargle periodogram, which is optimized for sine-like variations, TLS specifically models the geometric shape of planetary transits, making it significantly more effective at detecting shallow dips in stellar brightness caused by orbiting planets. This skill provides a complete workflow for processing light curve data, from cleaning outliers and flattening trends to searching for periodic signals and masking detected candidates to identify multi-planet systems.

• Performs non-sinusoidal transit model fitting to detect planetary signals with high precision.

• Handles raw light curve data including time, flux, and critical flux uncertainties.

• Integrates with the Lightkurve package for efficient data handling and preprocessing.

• Includes robust features for period refinement, phase-folding, and visual model validation.

• Facilitates iterative discovery of multiple planets via systematic transit masking and secondary signal searches.

• Calculates standard astrophysical metrics such as Signal Detection Efficiency (SDE), Signal-to-Noise Ratio (SNR), transit depth, and epoch-based transit timings.

• Ensure input data includes flux_err (flux uncertainties) to prevent inaccurate detection results.

• Use a two-stage approach: conduct a broad global search first, followed by a narrow grid refinement around identified candidate periods to achieve higher precision.

• Interpret SDE values greater than 6 as potential candidates and greater than 9 as strong detections; evaluate SNR scores against a threshold of 7.

• Be aware of potential period aliasing in data with gaps, particularly if the algorithm suggests testing multiples of the discovered period.

• Recommended preprocessing pipeline: remove sigma-clipping outliers, flatten the light curve to remove instrumental trends, then apply the TLS power search.

• Ideal for processing high-cadence photometric observations, identifying T0 (transit epoch) and calculating planetary transit parameters for further characterization.