Variability of hot sub-luminous stars and binaries: Machine learning analysis of Gaia DR3 multi-epoch photometry
| Autor: | Ranaivomanana, P., Uzundag, M., Johnston, C., Groot, P. J., Kupfer, T., Aerts, C. |
|---|---|
| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Hot sub-luminous stars represent a population of stripped and evolved red giants located at the Extreme Horizontal Branch (EHB). Since they exhibit a wide range of variability due to pulsations or binary interactions, unveiling their intrinsic and extrinsic variability is crucial for understanding the physical processes responsible for their formation. In the Hertzsprung-Russell diagram, they overlap with interacting binaries such as Cataclysmic Variables (CVs). By leveraging cutting-edge clustering algorithm tools, we investigate the variability of 1,576 hot subdwarf variable candidates using comprehensive data from Gaia DR3 multi-epoch photometry and Transiting Exoplanet Survey Satellite (TESS) observations. We present a novel approach that utilises the t-distributed stochastic neighbor embedding (t-SNE) and the Uniform Manifold Approximation and Projection (UMAP) dimensionality reduction algorithms to facilitate the identification and classification of different populations of variable hot subdwarfs and Cataclysmic Variables in a large dataset. In addition to the Gaia time-series statistics table, we adopt extra statistical features that enhance the performance of the algorithms. The clustering results lead to the identification of 85 new hot subdwarf variables based on Gaia and TESS lightcurves and 108 new variables based on Gaia lightcurves alone, including reflection-effect systems, HW Vir, ellipsoidal variables, and high-amplitude pulsating variables. A significant number of known Cataclysmic Variables (140) distinctively cluster in the 2-D feature space among an additional 152 objects that we consider new Cataclysmic Variable candidates. This study paves the way for more efficient and comprehensive analyses of stellar variability from both ground and space-based observations, as well as the application of machine learning classifications of variable candidates in large surveys. Comment: Resubmitted to Astronomy & Astrophyiscs, after having taken into account the positive minor referee comments; 11 pages, 9 figures, 1 table, 1 appendix (3 additional figures, 10 additional tables) |
| Databáze: | arXiv |
| Externí odkaz: |
|