VARTOOLS: A Program for Analyzing Astronomical Time-Series Data

TL;DR

VARTOOLS is an open-source command-line program in C for comprehensive analysis of astronomical light curves, supporting various algorithms for signal detection, filtering, modeling, and simulation, optimized for large-scale surveys.

Contribution

This paper introduces VARTOOLS, a versatile and extensible software package that consolidates numerous light curve analysis routines into a single, efficient tool for large astronomical datasets.

Findings

Supports multiple periodogram and transit search algorithms

Enables batch processing and parallel computation

Includes tools for noise characterization and light curve simulation

Abstract

This paper describes the VARTOOLS program, which is an open-source command-line utility, written in C, for analyzing astronomical time-series data, especially light curves. The program provides a general-purpose set of tools for processing light curves including signal identification, filtering, light curve manipulation, time conversions, and modeling and simulating light curves. Some of the routines implemented include the Generalized Lomb-Scargle periodogram, the Box-Least Squares transit search routine, the Analysis of Variance periodogram, the Discrete Fourier Transform including the CLEAN algorithm, the Weighted Wavelet Z-Transform, light curve arithmetic, linear and non-linear optimization of analytic functions including support for Markov Chain Monte Carlo analyses with non-trivial covariances, characterizing and/or simulating time-correlated noise, and the TFA and SYSREM filtering algorithms, among others. A mechanism is also provided for incorporating a user's own compiled processing routines into the program. VARTOOLS is designed especially for batch processing of light curves, including built-in support for parallel processing, making it useful for large time-domain surveys such as searches for transiting planets. Several examples are provided to illustrate the use of the program.