Stellar blend image classification using computationally efficient Gaussian processes

Abstract

Stellar blends, where two or more stars appear blended in an image, pose a significant visualization challenge in astronomy. Traditionally, distinguishing these blends from single stars has been costly and resource-intensive, involving sophisticated equipment and extensive expert analysis. This is especially problematic for analyzing the vast data volumes from surveys, such as Legacy Survey of Space and Time (LSST), Sloan Digital Sky Survey (SDSS), Dark Energy Spectroscopic Instrument (DESI), Legacy Imaging Survey and the Zwicky Transient Facility (ZTF). To address these challenges, we apply different normalizations and data embeddings on low resolution images of single stars and stellar blends, which are passed as inputs into machine learning methods and to a computationally efficient Gaussian process model (MuyGPs). MuyGPs consistently outperforms the benchmarked models, particularly on limited training data. Moreover, under the corresponding preprocessing and embedding pipeline, MuyGPs with rth root local min-max normalization achieved 83.8% accuracy. Furthermore, because MuyGPs provides predictive uncertainty estimates, it may be useful in downstream human-in-the-loop workflows, such as flagging low-confidence predictions for specialist review.