The white-light superflares from cool stars in GWAC triggers

Abstract

M-type stars are the ones that flare most frequently, but how big their maximum flare energy can reach is still unknown. We present 163 flares from 162 individual M2 through L1-type stars that triggered the GWAC, with flare energies ranging from $10^{32.2}$ to $10^{36.4}$ erg . The flare amplitudes range from $△G=0.84$ to $\sim 10$ mag. Flare energy increases with stellar surface temperature ($T_{\mathrm{eff}}$) but both $△G$ and equivalent duration ${\log }_{10}(ED)$ seem to be independent of $T_{\mathrm{eff}}$. Combining periods detected from light curves of TESS and K2, spectra from LAMOST, SDSS and the 2.16 m Telescope, and the Gaia DR3 data, we found that these GWAC flare stars are young. For the stars that have spectra, we found that these stars are in or very near to the saturation region, and ${\log }_{10}(L_{\mathrm{H}\alpha }/L_{\mathrm{bol}})$ is lower for M7-L1 stars than for M2-M6 stars. We also studied the relation between GWAC flare bolometric energy $E_{\mathrm{bol}}$ and stellar hemispherical area $S$, and found that ${\log }_{10}{E}_{\mathrm{bol}}$ (in erg) increases with increasing $S$ (in cm${}^2$), and the maximum flare energy ${\log }_{10}{E}_{\mathrm{bol},\max }⩾{\log }_{10}S+14.25$. For M7-L1 stars, there seem to be other factors limiting their maximum flare energies in addition to stellar hemispherical area.

arXiv comment18 pages, 11 figures, 4 tables

References in corpus (63)

• Astropy: A Community Python Package for Astronomy
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Local Kinematics and the Local Standard of Rest
• The stellar activity-rotation relationship and the evolution of stellar dynamos
• Improving PARSEC models for very low mass stars
• The Transiting Exoplanet Survey Satellite: Simulations of planet detections and astrophysical false positives
• LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The survey science plan
• Superflares on Solar Type Stars Observed with Kepler I. Statistical Properties of Superflares
• Rotation and Activity in Mid-M to L Dwarfs
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• Stellar Flares from the First Tess Data Release: Exploring a New Sample of M-dwarfs
• The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8
• The stellar rotation--activity relationship in fully convective M dwarfs
• Time-Resolved Properties and Global Trends in dMe Flares from Simultaneous Photometry and Spectra
• Can Superflares Occur on Our Sun?
• Activity in Very Cool Stars: Magnetic Dissipation in late-M and L Dwarf Atmospheres
• Modeling Repeated M-dwarf Flaring at an Earth-like Planet in the Habitable Zone: I. Atmospheric Effects for an Unmagnetized Planet
• Generalized investigation of the rotation-activity relation: Favouring rotation period instead of Rossby number
• Solar-type dynamo behaviour in fully convective stars without a tachocline
• The Origin of RNA Precursors on Exoplanets
• CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions
• From Radio to X-ray: Flares on the dMe Flare Star EV Lacertae
• Do Kepler superflare stars really include slowly-rotating Sun-like stars ? - Results using APO 3.5m telescope spectroscopic observations and Gaia-DR2 data -
• Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. III. X-ray, Radio, and H-alpha Activity Trends in M and L Dwarfs
• The flare catalog and the flare activity in the Kepler mission
• Persistence of Flare-Driven Atmospheric Chemistry on Rocky Habitable Zone Worlds
• BOSS Ultracool Dwarfs I: Colors and Magnetic Activity of M and L dwarfs
• Post-common envelope binaries from SDSS - XIV. The DR7 white dwarf-main sequence binary catalogue
• A Survey for New Members of Taurus from Stellar to Planetary Masses
• 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
• EvryFlare I: Long-term Evryscope Monitoring of Flares from the Cool Stars Across Half the Southern Sky
• Calibration of the Halpha Age-Activity relation for M dwarfs
• Evaluating Rotation Periods of M Dwarfs Across the Ages
• Statistical Analysis of Stellar Flares from the First Three Years of TESS Observations
• The largest M dwarfs flares from ASAS-SN
• ASASSN-16ae: A Powerful White-Light Flare on an Early-L Dwarf
• Stellar flares detected with the Next Generation Transit Survey
• Rotation-activity relations and flares of M dwarfs with K2 long- and short-cadence data
• 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
• The Impact of Stellar Distances on Habitable Zone Planets
• Detection of Flare-associated CME Candidates on Two M-dwarfs by GWAC and Fast, Time-resolved Spectroscopic Follow-ups
• Characteristic time of stellar flares on Sun-like stars
• Impact of stellar flares on the chemical composition and transmission spectra of gaseous exoplanets orbiting M dwarfs
• Stellar Flares versus Luminosity: XUV-induced Atmospheric Escape and Planetary Habitability
• The Grand Aurorae Borealis Seen in Colombia in 1859
• An Automatic Observation Management System of the GWAC Network I: System Architecture and Workflow
• Detection of a giant white-light flare on an L2.5 dwarf with the Next Generation Transit Survey
• The Ca II H&K Rotation-Activity Relation in 53 mid-to-late type M-Dwarfs
• Superflare UV flashes impact on Kepler-96 system: a glimpse of habitability when the ozone layer first formed on Earth
• Prompt-to-afterglow transition of optical emission in a long gamma-ray burst consistent with a fireball
• A Knee-Point in the Rotation-Activity Scaling of Late-type Stars with a Connection to Dynamo Transitions
• Main-sequence star super-flares based on entire Kepler data
• A $\Delta R\sim 9.5$ mag Super Flare of An Ultracool Star Detected by $\text{SVOM/GWAC}$ System
• Flaring-associated Complex Dynamics in Two M-dwarfs Revealed by Fast, Time-resolved Spectroscopy
• Photometric observations of flares on AD Leo from GWAC-F30 and TESS
• Estimating the Convective Turnover Time
• Magnetic activities and parameters of 43 flare stars in the GWAC archive
• Investigating the Efficiency of the Beijing Faint Object Spectrograph and Camera (BFOSC) of the Xinglong 2.16-m Reflector
• ELM of ELM-WD: An extremely low mass hot star discovered in LAMOST survey
• A huge-amplitude white-light superflare on a L0 brown dwarf discovered by GWAC survey

Cited by in corpus (2)

• CaII and H$\alpha$ flaring M dwarfs detected with multi-filter photometry
• Locate a stellar flare from the M dwarf LAMOST J1332+5057