Stellar flare morphology with TESS across the main sequence

Abstract

Stellar flares are abundant in space photometric light curves. As they are now available in large enough numbers, the statistical study of their overall temporal morphology is timely. We use light curves from the Transiting Exoplanet Survey Satellite (TESS) to study the shapes of stellar flares beyond a simple parameterization by duration and amplitude, and reveal possible connections to astrophysical parameters. We retrain and use the flatwrm2 long-short term memory neural network to find stellar flares in 2-min cadence TESS light curves from the first five years of the mission (sectors 1-69). We scale these flares to a comparable standard shape, and use principal component analysis to describe their temporal morphology in a concise way. We investigate how the flare shapes change along the main sequence, and test whether individual flares hold any information about their host stars. We also apply similar techniques to solar flares, using extreme ultraviolet irradiation time series. Our final catalog contains ~120,000 flares on ~14,000 stars. Due to the strict filtering and the final manual vetting, this sample contains virtually no false positives, although at the expense of reduced completeness. Using this flare catalog, we detect a dependence of the average flare shape on the spectral type. These changes are not apparent for individual flares, only when averaging thousands of events. We find no strong clustering in the flare shape space. We create new analytical flare templates for different types of stars, present a technique to sample realistic flares, and a method to locate flares with similar shapes. The flare catalog, along with the extracted flare shapes, and the data used to train flatwrm2 are publicly available.

19 pages, 23 figures, accepted to A&A. Supplementary material: https://zenodo.org/records/14179313

References in corpus (77)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The NumPy array: a structure for efficient numerical computation
• Gaia Data Release 2. Summary of the contents and survey properties
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• The PLATO 2.0 Mission
• Information criteria for astrophysical model selection
• The Revised TESS Input Catalog and Candidate Target List
• Kepler Flares I. Active and Inactive M dwarfs
• Stellar Flares from the First Tess Data Release: Exploring a New Sample of M-dwarfs
• Improving the open cluster census. II. An all-sky cluster catalogue with Gaia DR3
• The Kepler Catalog of Stellar Flares
• CMasher: Scientific colormaps for making accessible, informative and 'cmashing' plots
• Kepler Flares II: The Temporal Morphology of White-Light Flares on GJ 1243
• Time-Resolved Properties and Global Trends in dMe Flares from Simultaneous Photometry and Spectra
• eleanor: An open-source tool for extracting light curves from the TESS Full-Frame Images
• Statistical properties of superflares on solar-type stars based on 1-min cadence data
• A model for magnetically coupled sympathetic eruptions
• Probable detection of an eruptive filament from a superflare on a solar-type star
• Flare Statistics for Young Stars from a Convolutional Neural Network Analysis of $\text{TESS}$ Data
• Indications of stellar coronal mass ejections through coronal dimmings
• The flare catalog and the flare activity in the Kepler mission
• The quest for stellar coronal mass ejections in late-type stars: I. Investigating Balmer-line asymmetries of single stars in Virtual Observatory data
• Superflare occurrence and energies on G-, K- and M-type dwarfs
• Multi-Thread Hydrodynamic Modeling of a Solar Flare
• MOST Observations of our Nearest Neighbor: Flares on Proxima Centauri
• Weighted principal component analysis: a weighted covariance eigendecomposition approach
• Solar System objects observed with TESS -- First data release: bright main-belt and Trojan asteroids from the Southern Survey
• Stellar flares observed in long cadence data from the Kepler mission
• No Such Thing as a Simple Flare: Substructure and QPPs Observed in a Statistical Sample of 20 Second Cadence TESS Flares
• EvryFlare III: Temperature Evolution and Habitability Impacts of Dozens of Superflares Observed Simultaneously by Evryscope and TESS
• M Dwarf Flare Continuum Variations on One-Second Timescales: Calibrating and Modeling of ULTRACAM Flare Color Indices
• A search for flares and mass ejections on young late-type stars in the open cluster Blanco-1
• The Asteroseismic Target List (ATL) for solar-like oscillators observed in 2-minute cadence with the Transiting Exoplanet Survey Satellite (TESS)
• MOST Observations of the Flare Star AD Leo
• MOBSTER - II. Identification of rotationally variable A stars observed with \emph{TESS} in Sectors 1 to 4
• Flares, Rotation, and Planets of the AU Mic System from TESS Observations
• Superflares and Variability in Solar-Type Stars with $TESS$ in the Southern Hemisphere
• Statistical Analysis of Stellar Flares from the First Three Years of TESS Observations
• Finding flares in Kepler data using machine learning tools
• A census of Coronal Mass Ejections on solar-like stars
• Magnetic Flux and Magnetic Non-potentiality of Active Regions in Eruptive and Confined Solar Flares
• Galactic Kinematics and Observed Flare Rates of a Volume-Complete Sample of Mid-to-Late M-dwarfs: Constraints on the History of the Stellar Radiation Environment of Planets Orbiting Low-mass Stars
• Constraining the Physical Properties of Stellar Coronal Mass Ejections with Coronal Dimming: Application to Far Ultraviolet Data of $\epsilon$ Eridani
• Extending Optical Flare Models to the UV: Results from Comparing of TESS and GALEX Flare Observations For M Dwarfs
• Periodic variable A-F spectral type stars in the northern TESS continuous viewing zone
• A Data-driven Study of RR Lyrae Near-IR Light Curves: Principal Component Analysis, Robust Fits, and Metallicity Estimates
• Do long-cadence data of {\it Kepler} satellite capture the basic properties of flares ?
• The Connection between Starspots and Flares on Main-Sequence Kepler Stars
• Testing Self-Organized Criticality Across the Main Sequence using Stellar Flares from TESS
• Activity of TRAPPIST-1 analogue stars observed with TESS
• Fast optical flares from M dwarfs detected by a one-second-cadence survey with Tomo-e Gozen
• A Study of Flares in the Ultra-Cool Regime from SPECULOOS-South
• Finding flares in Kepler and TESS data with recurrent deep neural networks
• TESS observations of flares and quasi-periodic pulsations from low mass stars and potential impact on exoplanets
• Superflares on the late-type giant KIC 2852961 -- Scaling effect behind flaring at different energy levels
• A Bayesian method for detecting stellar flares
• Searching for quasi-periodic oscillations in astrophysical transients using Gaussian processes
• Extending the FIP bias sample to magnetically active stars. Challenging the FIP bias paradigm?
• Starspots Modelling and Flare Analysis on Selected MV Stars
• The Flaring TESS Objects of Interest: Flare Rates for all Two Minute Cadence TESS Planet Candidates
• The morphology of average solar flare time profiles from observations of the Sun's lower atmosphere
• Towards the true number of flaring giant stars in the Kepler field. Are there flaring specialities associated with the giant nature?
• Stellar Flares Are Far-Ultraviolet Luminous
• Flares hunting in hot subdwarf and white dwarf stars from Cycles 1-5 of TESS photometry
• Characteristics of flares on giant stars
• Simulating Solar Flare Irradiance with Multithreaded Models of Flare Arcades
• Lower-than-expected flare temperatures for TRAPPIST-1
• Bayesian evidence estimation from posterior samples with normalizing flows
• Minute-cadence Observations of the LAMOST Fields with the TMTS: III. Statistic Study of the Flare Stars from the First Two Years
• Observed Rate Variation in Superflaring G-type Stars
• Shape-based clustering of synthetic Stokes profiles using k-means and k-Shape
• Visualizing the pulsar population using graph theory
• The effect of emission lines on the performance of photometric redshift estimation algorithms
• Convolutional Neural Networks for Searching Superflares from Pixel-level Data of the Transiting Exoplanet Survey Satellite
• Doubling of minute-long Quasi-Periodic Pulsations from super-flares on a low mass star
• GalaxyFlow: Upsampling Hydrodynamical Simulations for Realistic Mock Stellar Catalogs
• Vela Pulsar: Single Pulses Analysis with Machine Learning Techniques

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• Enhancing the detection of low-energy M dwarf flares: Wavelet-based denoising of CHEOPS data
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• Homogeneous search for spot transits in Kepler and TESS photometry of K $-$ M-type main-sequence stars
• Radio emission from flaring stars and brown dwarfs
• Einstein Probe Discovery of an X-ray Flare from K-type Star PM J23221-0301