Title: VaST: a variability search toolkit Author: Kirill V. Sokolovsky, Alexandr A. Lebedev
Variability Search Toolkit (VaST) is a software package designed to find variable objects in a series of sky images. It relies on source list matching (as opposed to image subtraction) using SExtractor for source detection and aperture or PSF-fitting photometry (using PSFEx). Variability indices that characterize scatter and smoothness of the lightcurve are computed for all objects. Candidate variables are identified as objects having a variability index value significantly higher than other objects of similar brightness. The distinguishing features of VaST are the ability to conduct accurate aperture photometry using images obtained with non-linear detectors and handle complex image distortions. The software was successfully applied to images obtained with telescopes ranging from 0.08 to 2.5m in diameter equipped with a variety of detectors including CCD, CMOS, MIC and photographic plates. About 1800 variable stars have been discovered with VaST. It is used as the transient detection engine in the NMW nova patrol. The code is written in C and can work on many UNIX-like systems. VaST is free software available at this http URL