Inactive longitude and superflare in the active single-lined pre-main sequence binary V2279 Cyg

Abstract

Young, solar-like stars in the pre-main sequence (PMS) stage exhibit vigorous magnetic activity that significantly influences their circumstellar environments and the processes of planetary formation and evolution. In binary systems, tidal forces and magnetic interactions can further shape the magnetic geometry. We report a longitudinal preference of star spots, chromospheric activities, and flares in the active single-lined spectroscopic PMS binary system V2279 Cyg, based on long-term photometric observations from \textit{Kepler} and \textit{TESS} alongside spectroscopic data from LAMOST. The system is classified as a weak-line T Tauri binary, with component masses estimated at 0.86 $M_{\odot }$ and 0.27 $M_{\odot }$. V2279 Cyg's nearly circular orbit is synchronized with its 4.126-day rotational period. Observations reveal large star spot regions clustered near the far-side hemisphere. Spectroscopic data show strong, double-peak H$\alpha$ emission, the strength of which is highly correlated with star spot distribution, indicating the presence of an active longitude on the primary star. We also mapped the prominence structure co-rotating with the primary star, suggesting a dense structure close to the near-side hemisphere. Furthermore, we identify an inactive longitude of flares during the 4-year \textit{Kepler} observations, where the frequency of flare activity is significantly reduced after the superior conjunction, marking the first such identification in active binary systems. Additionally, a white light superflare, releasing energy of $2.5\times 10^{37}$ erg, was detected in \textit{TESS} observations. These findings provide valuable insights into the magnetic field geometry and dynamo processes in PMS binaries, underscoring the critical role of tidal interactions in shaping magnetic activities.

23 pages, 16 figures. Accepted by ApJ

References in corpus (73)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• 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
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Modules for Experiments in Stellar Astrophysics (MESA)
• The Transiting Exoplanet Survey Satellite
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Kepler Mission Design, Realized Photometric Performance, and Early Science
• A Computational Guide to Physics of Eclipsing Binaries. Paper I. Demonstrations and Perspectives
• Stellar magnetism: empirical trends with age and rotation
• Improved angular momentum evolution model for solar-like stars
• Physics Of Eclipsing Binaries. II. Towards the Increased Model Fidelity
• Kepler Data Validation II -- Transit Model Fitting and Multiple-Planet Search
• The Payne: self-consistent ab initio fitting of stellar spectra
• Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I -- methods and content overview
• Physics of Eclipsing Binaries. V. General Framework for Solving the Inverse Problem
• Deep learning of multi-element abundances from high-resolution spectroscopic data
• A new library of theoretical stellar spectra with scaled-solar and alpha-enhanced mixtures
• 2SXPS: An improved and expanded Swift X-ray telescope point source catalog
• LAMOST observations in the Kepler field. Database of low-resolution spectra
• The evolution of surface magnetic fields in young solar-type stars II: The early main sequence (250-650 Myr)
• Activity indicators and stellar parameters of the Kepler targets. An application of the ROTFIT pipeline to LAMOST-Kepler stellar spectra
• The evolution of the solar wind
• Resolved young binary systems and their disks
• Self-consistent Stellar Radial Velocities from LAMOST Medium-Resolution Survey (MRS) DR7
• The Magnetic Topology of the Weak-Lined T Tauri Star V410 - A Simultaneous Temperature and Magnetic Field Inversion
• Physics of Eclipsing Binaries. III. Spin-Orbit Misalignment
• Physics of Eclipsing Binaries. IV. The impact of interstellar extinction on the light curves of eclipsing binaries
• Magnetic activity and hot Jupiters of young Suns: the weak-line T Tauri stars V819 Tau and V830 Tau
• LAMOST observations in the Kepler field. II. Database of the low-resolution spectra from the five-year regular survey
• Phase II of the LAMOST-Kepler/K2 survey. I. Time series of medium-resolution spectroscopic observations
• Studying stellar spin-down with Zeeman-Doppler magnetograms
• Rotation Period Evolution in Low-Mass Binary Stars: The Impact of Tidal Torques and Magnetic Braking
• Rapid Rotation in the Kepler Field: Not a Single Star Phenomenon
• Impacts of stellar evolution and dynamics on the habitable zone: The role of rotation and magnetic activity
• Finding flares in Kepler data using machine learning tools
• Supersaturation and activity-rotation relation in PMS stars: the young Cluster h Per
• What sets the magnetic field strength and cycle period in solar-type stars?
• Overview of the LAMOST-$Kepler$ project
• Tides in asynchronous binary systems
• The weak-line T Tauri star V410Tau I. A multi-wavelength study of variability
• Active Longitude and Solar Flare Occurrences
• Searching for ZZ Ceti White Dwarfs in the Gaia Survey
• Spots, flares, accretion, and obscuration in the pre-main sequence binary DQ Tau
• Magnetic topologies of young suns: The weak-line T Tauri stars TWA 6 and TWA 8A
• Magnetic field and prominences of the young, solar-like, ultra-rapid rotator V530 Per
• LAMOST Observations in 15 \textit{K}2 Campaigns: I. Low resolution spectra from LAMOST DR6
• Spurious 'active longitudes' in parametric models of heavily spotted eclipsing binaries
• Cepheid investigations using the Kepler space telescope
• Time-series Doppler imaging of the red giant HD 208472. Active longitudes and differential rotation
• Towards the true number of flaring giant stars in the Kepler field. Are there flaring specialities associated with the giant nature?
• Accurate and Robust Stellar Rotation Periods catalog for 82771 Kepler stars using deep learning
• Slingshot prominence evolution for a solar-like star
• Flares hunting in hot subdwarf and white dwarf stars from Cycles 1-5 of TESS photometry
• The active weak-line T Tauri star LkCa 4 observed with SPIRou and TESS
• Characteristics of flares on giant stars
• Characterization of Kepler targets based on medium-resolution LAMOST spectra analyzed with ROTFIT
• Starspot evolution, Differential Rotation and Correlation between Chromospheric and Photospheric Activities on Kepler-411
• Magnetic field and activity phenomena of the K2 dwarf V471 Tau
• The Surface Magnetic Activity of the Weak-Line T Tauri Stars TWA 7 and TWA 25
• The Surface Magnetic Activity of the Weak-Line T Tauri Stars TWA 9A and V1095 Sco
• The role of magnetic fields in pre-main sequence stars
• Slingshot prominences: a hidden mass loss mechanism
• Spot modelling of periodic weak-line T Tauri stars observed by CoRoT in NGC 2264
• Stellar activity and planetary atmosphere evolution in tight binary star systems
• Short-term variations of surface magnetism and prominences of the young Sun-like star V530 Per
• Magnetic field evolution of the K2 dwarf V471 Tau
• Estimations and scaling laws for stellar magnetic fields