Predictability of bursts of a recurrent nova using topological data analysis and machine learning
Ignacio Morales-Gil
TL;DR
The paper addresses predicting bursts in the recurrent nova RS Ophiuchi from optical lightcurves, tackling non-periodicity by applying topological data analysis (TDA). It builds persistence diagrams from ordinal partition networks of lightcurve segments and featurizes them with multiple representations, then uses tenfold cross-validated supervised classification to predict whether a burst will occur within $1$ year. Persistence landscapes offered the best performance, achieving approximately $0.93$ accuracy on the test set and around $0.96$ recall for pre-burst intervals, indicating strong predictive power and potential for targeted follow-up observations in astronomical surveys. The work demonstrates the practical value of TDA in astronomy, suggesting extensions to regression and other data modalities such as spectra and images, thereby enabling earlier and more reliable transient alerts.
Abstract
RS Oph is a recurrent nova, a kind of cataclismic variable that shows bursts in a period approximately shorter than a century. Persistent homology, a technique from topological data analysis, studies the evolution of topological features of a simplicial complex composed of the data points or an embedding of them, as some distance parameter is varied. For this work I trained a supervised learning model based on several featurizations, namely persistence landscapes, Carlsson coordinates, persistent images, and template functions, of the persistence diagrams of sections of the lightcurve of RS Oph. A tenfold cross validation of the model based on one of the featurizations, persistence landscapes, consistently shows high recalls and accuracies. This method serves the purpose of predicting whether RS Oph is bursting within a year.
