Accretion and Magnetic Reconnection in the Classical T Tauri Binary DQ Tau

Abstract

Binary star-formation theory predicts that close binaries (a<100 AU) will experience periodic pulsed accretion events as streams of material form at the inner edge of a circumbinary disk, cross a dynamically cleared gap, and feed circumstellar disks or accrete directly onto the stars. The archetype for the pulsed-accretion theory is the eccentric, short-period, classical T Tauri binary DQ Tau. Low-cadence (~daily) broadband photometry has shown brightening events near most periastron passages, just as numerical simulations would predict for an eccentric binary. Magnetic reconnection events (flares) during the collision of stellar magnetospheres near periastron could, however, produce the same periodic, broadband behavior when observed at a one-day cadence. To reveal the dominate physical mechanism seen in DQ Tau's low-cadence observations, we have obtained continuous, moderate-cadence, multi-band photometry over 10 orbital periods, supplemented with 27 nights of minute-cadence photometry centered on 4 separate periastron passages. While both accretion and stellar flares are present, the dominant timescale and morphology of brightening events are characteristic of accretion. On average, the mass accretion rate increases by a factor of 5 near periastron, in good agreement with recent models. Large variability is observed in the morphology and amplitude of accretion events from orbit-to-orbit. We argue this is due to the absence of stable circumstellar disks around each star, compounded by inhomogeneities at the inner edge of the circumbinary disk and within the accretion streams themselves. Quasi-periodic apastron accretion events are also observed, which are not predicted by binary accretion theory.

Accepted to ApJ, 17 pages, 11 figures

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Cited by in corpus (21)

• The JCMT Transient Survey: Detection of sub-mm variability in a Class I protostar EC 53 in Serpens Main
• The Effect of Binarity on Circumstellar Disk Evolution
• Pulsed Accretion in the T Tauri Binary TWA 3A
• Star-disk interactions in multi-band photometric monitoring of the classical T Tauri star GI Tau
• Large amplitude periodic outbursts and long period variables in the VVV VIRAC2-$\beta$ database
• Mass-accretion, spectral, and photometric properties of T Tauri stars in Taurus based on TESS and LAMOST
• The Inner Disk and Accretion Flow of the Close Binary DQ Tau
• Optical and Radio Observations of the T Tauri Binary KH 15D (V582 Mon): Stellar Properties, Disk Mass Limit and Discovery of a CO Outflow
• The centimeter emission from planet-forming disks in Taurus
• The accretion process in the DQ Tau binary system
• Frequent flare events on the short-period M-type eclipsing binary BX Tri
• Ro-vibrational Spectroscopy of CI Tau -- Evidence of a Multi-Component Eccentric Disk Induced by a Planet
• A Low-Mass Pre-Main-Sequence Eclipsing Binary in Lower Centaurus Crux Discovered with TESS
• Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Characterization of the young star T CrA and its circumstellar environment
• Discovery of Magnetospheric Interactions in the Doubly-Magnetic Hot Binary $\epsilon$ Lupi
• The Young Binary DQ Tau Produces Another X-ray Flare Near Periastron
• Spots, flares, accretion, and obscuration in the pre-main sequence binary DQ Tau
• Accretion process, magnetic fields, and apsidal motion in the pre-main sequence binary DQ Tau
• The influence of tight binaries on proto-planetary disk masses
• Accretion Kinematics in the T Tauri Binary TWA 3A: Evidence for Preferential Accretion onto the TWA 3A Primary
• Exploring Young Stellar Variability with Gaia DR3 light curves