The ASAS-SN catalogue of variable stars - II. Uniform classification of 412 000 known variables

Abstract

The variable stars in the VSX catalogue are derived from a multitude of inhomogeneous data sources and classification tools. This inhomogeneity complicates our understanding of variable star types, statistics, and properties, and it directly affects attempts to build training sets for current (and next) generation all-sky, time-domain surveys. We homogeneously analyse the All-Sky Automated Survey for SuperNovae (ASAS-SN) V-band light curves of ∼412 000 variables from the VSX catalogue. The variables are classified using an updated random forest classifier with an F1 score of 99.4 per cent and refinement criteria for individual classifications. We have derived periods for ∼52 000 variables in the VSX catalogue that lack a period, and have reclassified ∼17 000 sources into new broad variability groups with high confidence.We have also reclassified ∼94 000 known variables with miscellaneous/generic classifications. The light curves, classifications, and a range of properties of the variables are all available through the ASAS-SN Variable Stars Database (https://asas-sn.osu.edu/variables). We also include the V-band light curves for a set of ∼4000 rare variables and transient sources, including cataclysmic variables, symbiotic binaries, and flare stars.