The EPOCH Project: I. Periodic variable stars in the EROS-2 LMC database

Abstract

The EPOCH (EROS-2 periodic variable star classification using machine learning) project aims to detect periodic variable stars in the EROS-2 light curve database. In this paper, we present the first result of the classification of periodic variable stars in the EROS-2 LMC database. To classify these variables, we first built a training set by compiling known variables in the Large Magellanic Cloud area from the OGLE and MACHO surveys. We crossmatched these variables with the EROS-2 sources and extracted 22 variability features from 28 392 light curves of the corresponding EROS-2 sources. We then used the random forest method to classify the EROS-2 sources in the training set. We designed the model to separate not only $\delta$ Scuti stars, RR Lyraes, Cepheids, eclipsing binaries, and long-period variables, the superclasses, but also their subclasses, such as RRab, RRc, RRd, and RRe for RR Lyraes, and similarly for the other variable types. The model trained using only the superclasses shows 99% recall and precision, while the model trained on all subclasses shows 87% recall and precision. We applied the trained model to the entire EROS-2 LMC database, which contains about 29 million sources, and found 117 234 periodic variable candidates. Out of these 117 234 periodic variables, 55 285 have not been discovered by either OGLE or MACHO variability studies. This set comprises 1 906 $\delta$ Scuti stars, 6 607 RR Lyraes, 638 Cepheids, 178 Type II Cepheids, 34 562 eclipsing binaries, and 11 394 long-period variables. A catalog of these EROS-2 LMC periodic variable stars will be available online at http://stardb.yonsei.ac.kr and at the CDS website (http://vizier.u-strasbg.fr/viz-bin/VizieR).

18 pages, 20 figures, suggseted language-editing by the A&A editorial office is applied

References in corpus (4)

• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• New Optical Reddening Maps of the Large and Small Magellanic Clouds
• An improved quasar detection method in EROS-2 and MACHO LMC datasets
• The beat Cepheids in the Magellanic Clouds: an analysis from the EROS-2 database

Cited by in corpus (51)

• The Automatic Learning for the Rapid Classification of Events (ALeRCE) Alert Broker
• The wind speeds, dust content, and mass-loss rates of evolved AGB and RSG stars at varying metallicity
• Alert Classification for the ALeRCE Broker System: The Light Curve Classifier
• Gaia Data Release 3. The first Gaia catalogue of eclipsing binary candidates
• Gaia Data Release 3: All-sky classification of 12.4 million variable sources into 25 classes
• Comparative performance of selected variability detection techniques in photometric time series
• Gaia Data Release 1 - The Cepheid & RR Lyrae star pipeline and its application to the south ecliptic pole region
• Luminosities and mass-loss rates of Local Group AGB stars and Red Supergiants
• Binary Stars in the New Millennium
• Anomaly detection in the Zwicky Transient Facility DR3
• Machine learning search for variable stars
• Gaia Data Release 3: Cross-match of Gaia sources with variable objects from the literature
• Scalable End-to-end Recurrent Neural Network for Variable star classification
• Supervised detection of anomalous light-curves in massive astronomical catalogs
• The ASAS-SN Catalog of Variable Stars IV: Periodic Variables in the APOGEE Survey
• Unsupervised machine learning for transient discovery in Deeper, Wider, Faster light curves
• Unsupervised Classification of Variable Stars
• The ZTF Source Classification Project: I. Methods and Infrastructure
• LAMOST Time-Domain Survey: First Results of four $K$2 plates
• The QUEST-La Silla AGN Variability Survey: selection of AGN candidates through optical variability
• Deep Neural Network Classifier for Variable Stars with Novelty Detection Capability
• A random forest-based selection of optically variable AGN in the VST-COSMOS field
• Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey
• The VMC Survey -- XXXVII. Pulsation periods of dust enshrouded AGB stars in the Magellanic Clouds
• The VVV Infrared Variability Catalog (VIVA-I)
• Uncertain classification of Variable Stars: handling observational GAPS and noise
• Machine learning techniques to select Be star candidates. An application in the OGLE-IV Gaia south ecliptic pole field
• The effect of phased recurrent units in the classification of multiple catalogs of astronomical lightcurves
• Stellar chromospheric activities revealed from the LAMOST-K2 time-domain survey
• A helium-burning white dwarf binary as a supersoft X-ray source
• Streaming Classification of Variable Stars
• Deep Transfer Learning for Classification of Variable Sources
• SNAD Transient Miner: Finding Missed Transient Events in ZTF DR4 using k-D trees
• Zwicky Transient Facility and Globular Clusters: the Period-Luminosity and Period-Luminosity-Color Relations for Late-Type Contact Binaries
• Semi-Supervised Classification and Clustering Analysis for Variable Stars
• Selection of optically variable active galactic nuclei via a random forest algorithm
• The Hubble Catalog of Variables (HCV)
• LTD064402+245919: A Subgiant with a 1-3 M${}_{\odot }$ Undetected Companion Identified from LAMOST-TD Data
• Spectral energy distributions of classical cepheids in the Magellanic Clouds
• Automatic Catalog of RRLyrae from $\sim$ 14 million VVV Light Curves: How far can we go with traditional machine-learning?
• Time-domain study of the young massive cluster Westerlund 2 with the Hubble Space Telescope. I
• Finding radio transients with anomaly detection and active learning based on volunteer classifications
• Light Curve Classification with DistClassiPy: a new distance-based classifier
• Leveraging pre-trained vision Transformers for multi-band photometric light curve classification
• New variable sources revealed by DECam toward the LMC: the first 15 deg2
• Navigating AGN variability with self-organizing maps
• Multivariate time series transformer embeddings for light curves of periodic variable stars
• The largest ground-based catalogue of M-dwarf flares
• EROS light curve data base
• Classification of blazars based on data-driven approaches
• Identifying Periodic Variable Stars and Eclipsing Binary Systems with Long-Term Las Cumbres Observatory Photometric Monitoring of ZTF J0139+5245