Young Faithful: The Eruptions of EC 53 as It Cycles through Filling and Draining the Inner Disk

Abstract

While young stellar objects sometimes undergo bursts of accretion, these bursts usually occur sporadically, making them challenging to study observationally and to explain theoretically. We build a schematic description of cyclical bursts of the young stellar object EC 53 using near-IR and sub-mm monitoring obtained over six cycles, each lasting $\approx 530$ days. EC 53 brightens over $0.12$ yr by $0.3$ mag at 850 $\mu$m, $2$ mag at 3.35 $\mu$m, and $1.5$ mag at near-IR wavelengths, to a maximum luminosity consistent with an accretion rate of $\sim 8\times 10^{-6}$ M${}_{\odot }$ yr${}^{-1}$. The emission then decays with an e-folding timescale of $\approx 0.74$ yr until the accretion rate is $\sim 1\times 10^{-6}$ M${}_{\odot }$ yr${}^{-1}$. The next eruption then occurs, likely triggered by the buildup of $\sim 5\times 10^{-6}$ M${}_{\odot }$ of mass in the inner disk, enough that it becomes unstable and drains onto the star. Just before outburst, when the disk is almost replenished, the near-IR colors become redder, indicating an increase in the geometrical height of the disk by this mass buildup. The reddening disappears soon after the initial burst, as much of the mass is drained from the disk. We quantify physical parameters related to the accretion process in EC 53 by assuming an $\alpha$-disk formulation, constrained by the observed disk properties and accretion rate. While we can only speculate about the possible trigger for these faithful eruptions, we hope that our quantified schematic will motivate theorists to test the hypothesized mechanisms that could cause the cyclical buildup and draining of mass in the inner disk.

arXiv commentAccepted for publication in the Astrophysical Journal

References in corpus (64)

• Astropy: A Community Python Package for Astronomy
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• Understanding the Lomb-Scargle Periodogram
• The UKIRT Infrared Deep Sky Survey ZYJHK Photometric System: Passbands and Synthetic Colours
• Initial Performance of the NEOWISE Reactivation Mission
• SCUBA-2: The 10000 pixel bolometer camera on the James Clerk Maxwell Telescope
• Gravitational Instabilities in Circumstellar Disks
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• NEOWISE Observations of Near-Earth Objects: Preliminary Results
• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
• Assessing statistical significance of periodogram peaks
• On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga
• SCUBA-2: iterative map-making with the Sub-Millimetre User Reduction Facility
• Young Stellar Objects in the Gould Belt
• SCUBA-2: on-sky calibration using submillimetre standard sources
• Periodograms for Multiband Astronomical Time Series
• Episodic Accretion on to Strongly Magnetic Stars
• Evolutionary Signatures in the Formation of Low-Mass Protostars. II. Towards Reconciling Models and Observations
• Accretion Discs Trapped Near Corotation
• Long-term Evolution of Protostellar and Protoplanetary Disks. II. Layered Accretion with Infall
• A Near-IR Spectroscopic Survey of FU Orionis Objects
• The Hot Inner Disk of FU Ori
• Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts
• Viscous diffusion and photoevaporation of stellar disks
• The Gould's Belt Distances Survey (GOBELINS) III. The distance to the Serpens/Aquila Molecular Complex
• Measuring Protoplanetary Disk Accretion with H I Pf-beta
• Continuum Variability of Deeply Embedded Protostars as a Probe of Envelope Structure
• Accretion Outbursts in Self-gravitating Protoplanetary Disks
• Episodic molecular outflow in the very young protostellar cluster Serpens South
• Pulsed Accretion onto Eccentric and Circular Binaries
• Formation and survivability of giant planets on wide orbits
• Molecular jets from low-mass young protostellar objects
• The outburst and nature of two young eruptive stars in the North America/Pelican Nebula Complex
• The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution
• The 2008 extreme outburst of the young eruptive variable star Ex Lupi
• Fu Ori outbursts and the planet-disc mass exchange
• Gaia 17bpi: An FU Ori Type Outburst
• On the nature of the EXor accretion events: an unfrequent manifestation of a common phenomenology ?
• How do stars gain their mass? A JCMT/SCUBA-2 Transient Survey of Protostars in Nearby Star Forming Regions
• Determining the recurrence timescale of long-lasting YSO outbursts
• A Simple Calculation in Service of Constraining the Rate of FU Orionis Outburst Events from Photometric Monitoring Surveys
• Eruptive Variable Stars and Outflows in Serpens NW
• Gravitational fragmentation and formation of giant protoplanets on tens-of-au orbits
• Variable Accretion Outbursts in Protostellar Evolution
• Fundamental Vibrational Transition of CO during the Outburst of EX Lupi in 2008
• The JCMT Transient Survey: Detection of sub-mm variability in a Class I protostar EC 53 in Serpens Main
• Outbursts in Global Protoplanetary Disk Simulations
• The Relationship between Mid-Infrared and Sub-Millimetre Variability of Deeply Embedded Protostars
• A Very Compact Extremely High Velocity Flow toward MMS 5 / OMC-3 Revealed with ALMA
• Knotty protostellar jets as a signature of episodic protostellar accretion?
• Gaia 19ajj: A Young Star Brightening Due to Enhanced Accretion + Reduced Extinction
• EXor outbursts from disk amplification of stellar magnetic cycles
• Radiative Transfer modeling of EC 53: An Episodically Accreting Class I Young Stellar Object
• Depletion of molecular gas by an accretion outburst in a protoplanetary disk
• The JCMT Transient Survey: Identifying Submillimetre Continuum Variability over Several Year Timescales Using Archival JCMT Gould Belt Survey Observations
• Diagnosing 0.1-10 au scale morphology of the FU\,Ori disk using ALMA and VLTI/GRAVITY
• V346 Nor: the post-outburst life of a peculiar young eruptive star
• Observational signatures of outbursting protostars -- II: Exploring a wide range of eruptive protostars
• The circumstellar environment around the embedded protostar EC 53
• Observational signatures of outbursting protostars - I: From hydrodynamic simulations to observations
• High Resolution Optical and NIR Spectra of HBC 722
• Light curves of the latest FUor: Indication of a close binary
• Modelling hystereses observed during dwarf-nova outbursts

Cited by in corpus (19)

• CCAT-prime Collaboration: Science Goals and Forecasts with Prime-Cam on the Fred Young Submillimeter Telescope
• Quantifying Variability of YSOs in the Mid-IR Over Six Years with NEOWISE
• Diagnosing FUor-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-IR
• Analysis of physical processes in eruptive YSOs with near infrared spectra and multi-wavelength light curves
• Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A
• Dissecting the different components of the modest accretion bursts of the very young protostar HOPS 373
• Large amplitude periodic outbursts and long period variables in the VVV VIRAC2-$\beta$ database
• A kinematic perspective on the formation process of the stellar groups in the Rosette Nebula
• Accretion Burst Echoes as Probes of Protostellar Environments and Episodic Mass Assembly
• On the incidence of episodic accretion in Class I YSOs from VVV
• AGB interlopers in YSO catalogues hunted out by NEOWISE
• Periodic Eruptive Variability of the Isolated Pre-Main Sequence Star V347 Aurigae
• The JCMT Transient Survey: Single Epoch Transients and Variability of Faint Sources
• Photometric and Spectroscopic monitoring of YSOs in nearby star forming regions. I. Eruptive YSOs
• Accretion Burst Crystallizes Silicates in a Planet-Forming Disk
• Protostellar Outflows: a window to the past
• The JCMT Transient Survey: Four Year Summary of Monitoring the Submillimeter Variability of Protostars
• Icy Volatile Enhancements in Evolving Protoplanetary Disks
• Misaligned Circumstellar Disks and Orbital Motion of the Young Binary XZ Tau