Quantifying Variability of YSOs in the Mid-IR Over Six Years with NEOWISE

Abstract

Variability in young stellar objects (YSOs) can be caused by various time-dependent phenomena associated with star formation, including accretion rates, geometric changes in the circumstellar disks, stochastic hydromagnetic interactions between stellar surfaces and inner disk edges, reconnections within the stellar magnetosphere, and hot/cold spots on stellar surfaces. We uncover and characterize $\sim$1700 variables from a sample of $\sim$5400 YSOs in nearby low-mass star-forming regions using mid-IR light curves obtained from the 6.5-years NEOWISE All Sky Survey. The mid-IR variability traces a wide range of dynamical, physical, and geometrical phenomenon. We classify six types of YSO mid-IR variability based on their light curves: secular variability ($Linear,Curved,Periodic$) and stochastic variability ($Burst,Drop,Irregular$). YSOs in earlier evolutionary stages have higher fractions of variables and higher amplitudes for the variability, with the recurrence timescale of FUor-type outbursts (defined here as $\Delta$W1 or $\Delta$W2 $>1$ mag followed by inspection of candidates) of $\sim$1000 years in the early embedded protostellar phase. Known eruptive young stars and subluminous objects show fractions of variables similar to the fraction ($\sim 55\%$) found in typical protostars, suggesting that these two distinct types are not distinct in variability over the 6.5-year timescale. Along with brightness variability, we also find a diverse range of secular color variations, which can be attributed to a competitive interplay between the variable accretion luminosity of the central source and the variable extinction by material associated with the accretion process.

arXiv commentAccepted for publication in ApJ

References in corpus (133)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Transiting Exoplanet Survey Satellite
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The Spitzer Space Telescope Mission
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• The VizieR database of Astronomical Catalogues
• Understanding the Lomb-Scargle Periodogram
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• Initial Performance of the NEOWISE Reactivation Mission
• The UKIDSS Galactic Plane Survey
• The Spitzer Space Telescope Survey of the Orion A & B Molecular Clouds - Part I: A Census of Dusty Young Stellar Objects and a Study of their Mid-IR Variability
• NEOWISE Observations of Near-Earth Objects: Preliminary Results
• Properties of the Youngest Protostars in Perseus, Serpens, and Ophiuchus
• CSI 2264: Simultaneous optical and infrared light curves of young disk-bearing stars in NGC 2264 with CoRoT and Spitzer-- evidence for multiple origins of variability
• Accretion in Brown Dwarfs: an Infrared View
• Assessing statistical significance of periodogram peaks
• Near-Infrared Photometric Variability of Stars Toward the Orion A Molecular Cloud
• Young Stellar Objects in the Gould Belt
• Identifying the Low Luminosity Population of Embedded Protostars in the c2d Observations of Clouds and Cores
• The Role of Multiplicity in Disk Evolution and Planet Formation
• AGB Variables and the Mira Period-Luminosity Relation
• Magnetospheric accretion-ejection processes in the classical T Tauri star AA
• Intrinsically Red Sources observed by Spitzer in the Galactic Mid-Plane
• YSOVAR: the first sensitive, wide-area, mid-IR photometric monitoring of the ONC
• Imaging the water-snow line during a protostellar outburst
• The Herschel Orion Protostar Survey: Spectral Energy Distributions and Fits Using a Grid of Protostellar Models
• Variable protostellar accretion with episodic bursts
• Accretion to Magnetized Stars through the Rayleigh-Taylor Instability: Global Three-Dimensional Simulations
• Evolutionary Signatures in the Formation of Low-Mass Protostars. II. Towards Reconciling Models and Observations
• A Classification Scheme for Young Stellar Objects Using the WIDE-FIELD INFRARED SURVEY EXPLORER AllWISE Catalog: Revealing Low-Density Star Formation in the Outer Galaxy
• Accretion Discs Trapped Near Corotation
• 2-D simulations of FU Orionis disk outbursts
• A Near-IR Spectroscopic Survey of FU Orionis Objects
• Accretion dynamics and disk evolution in NGC 2264: a study based on the Corot photometric observations
• A Near-Infrared Spectroscopic Survey of Class I Protostars
• An unbiased search for the signatures of protostars in the rho Ophiuchi Molecular Cloud. II. Millimetre continuum observations
• Kinematic Structure of the Orion Nebula Cluster and its Surroundings
• Massive planets in FU Orionis discs: implications for thermal instability models
• Results of the ROTOR-program. II. The long-term photometric variability of weak-line T Tauri stars
• The ice composition in the disk around V883 Ori revealed by its stellar outburst
• Placing the spotted T Tauri star LkCa 4 on an HR diagram
• CSI 2264: Characterizing Accretion-Burst Dominated Light Curves for Young Stars in NGC 2264
• Tracing the Mass during Low-Mass Star Formation, IV: Observations and Modeling of the Submillimeter Continuum Emission from Class I Protostars
• AA Tau's sudden and long-lasting deepening: enhanced extinction by its circumstellar disk
• Class 0 Protostars in the Perseus Molecular Cloud: A Correlation Between the Youngest Protostars and the Dense Gas Distribution
• Continuum Variability of Deeply Embedded Protostars as a Probe of Envelope Structure
• Accretion Outbursts in Self-gravitating Protoplanetary Disks
• Episodic Accretion in Young Stars
• IN-SYNC IV - The Young Stellar Population in the Orion A Molecular Cloud
• A systematic survey for eruptive young stellar objects using mid-infrared photometry
• HOPS 383: An Outbursting Class 0 Protostar in Orion
• The outburst and nature of two young eruptive stars in the North America/Pelican Nebula Complex
• A population of eruptive variable protostars in VVV
• The Extraordinary Outburst in the Massive Protostellar System NGC6334I-MM1: Emergence of Strong 6.7 GHz Methanol Masers
• A Survey for New Members of Taurus from Stellar to Planetary Masses
• Infrared spectroscopy of eruptive variable protostars from VVV
• Episodic accretion, protostellar radiative feedback, and their role in low-mass star formation
• Mid-InfraRed Outburst in Nearby Galaxies (MIRONG) I: Sample Selection and Characterization
• UV variability and accretion dynamics in the young open cluster NGC 2264
• Gaia 17bpi: An FU Ori Type Outburst
• On the nature of the EXor accretion events: an unfrequent manifestation of a common phenomenology ?
• The Spitzer survey of interstellar clouds in the Gould Belt. II. The Cepheus Flare observed with IRAC and MIPS
• Catalogues of Active Galactic Nuclei From Gaia and unWISE Data
• A continuum of accretion burst behavior in young stars observed by K2
• How do stars gain their mass? A JCMT/SCUBA-2 Transient Survey of Protostars in Nearby Star Forming Regions
• PTF10nvg: An Outbursting Class I Protostar in the Pelican/North American Nebula
• Chronology of Episodic Accretion in Protostars -- an ALMA survey of the CO and H${}_2$O snowlines
• Self-consistent evolution of accreting low-mass stars and brown dwarfs
• The Evolution of Protostars: Insights from Ten Years of Infrared Surveys with Spitzer and Herschel
• The outburst of the eruptive young star OO Serpentis between 1995 and 2006
• Physical and chemical fingerprint of protostellar disc formation
• 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
• Constraining the Rate of Protostellar Accretion Outbursts in the Orion Molecular Clouds
• Initial results from a systematic search for changing-look active galactic nuclei selected via mid-infrared variability
• An initial overview of the extent and structure of recent star formation within the Serpens Molecular Cloud using Gaia Data Release 2
• The JCMT Transient Survey: Stochastic and Secular Variability of Protostars and Disks In the Sub-Millimeter Observed Over Eighteen Months
• Eruptive Variable Stars and Outflows in Serpens NW
• Embedded protostellar disks around (sub-)solar protostars. I. Disk structure and evolution
• Disk-Related Bursts and Fades in Young Stars
• YSOVAR: Mid-IR variability in the star forming region Lynds 1688
• A Submillimeter Burst of S255IR~SMA1 - The Rise And Fall Of Its Luminosity
• The JCMT Transient Survey: Data Reduction and Calibration Methods
• Discovery and Observations of ASASSN-13db, an EX Lupi-Type Accretion Event on a Low-Mass T Tauri Star
• Long-term variability of T Tauri stars using WASP
• The Relationship between Mid-Infrared and Sub-Millimetre Variability of Deeply Embedded Protostars
• Gaia 19ajj: A Young Star Brightening Due to Enhanced Accretion + Reduced Extinction
• Young Faithful: The Eruptions of EC 53 as It Cycles through Filling and Draining the Inner Disk
• The disappearing act: A dusty wind eclipsing RW Aur
• YSO jets in the Galactic Plane from UWISH2: II - Outflow Luminosity and Length distributions in Serpens and Aquila
• Giant protostellar flares: accretion-driven accumulation and reconnection-driven ejection of magnetic flux in protostars
• X-ray variability of PMS stars - Toward an explanation of the different X-ray properties of CTTS and WTTS
• Extreme infrared variables from UKIDSS - II. an end-of-survey catalogue of eruptive YSOs and unusual stars
• Pulsed Accretion in the T Tauri Binary TWA 3A
• A multi-wavelength census of star formation activity in the young embedded cluster around Serpens/G3-G6
• Radiative Transfer modeling of EC 53: An Episodically Accreting Class I Young Stellar Object
• Analysis of physical processes in eruptive YSOs with near infrared spectra and multi-wavelength light curves
• Extreme Infrared Variables from UKIDSS - I. A Concentration in Star Forming Regions
• The 2014-2017 outburst of the young star ASASSN-13db: A time-resolved picture of a very low-mass star between EXors and FUors
• Infrared two-colour diagrams for AGB stars using AKARI, MSX, IRAS and NIR data
• V409 Tau As Another AA Tau: Photometric Observations of Stellar Occultations by the Circumstellar Disk
• V346 Nor: the post-outburst life of a peculiar young eruptive star
• A Differential Measurement of Circumstellar Extinction for AA Tau's 2011 Dimming Event
• Characterising the i-band variability of YSOs over six orders of magnitude in timescale
• On the mid-IR variability of candidate eruptive variables (EXors): a comparison between Spitzer and WISE data
• Variability, periodicity and contact binaries in WISE
• Gaia DR2 view of the Lupus V-VI clouds: the candidate diskless young stellar objects are mainly background contaminants
• Variable dust emission by WC type Wolf-Rayet stars observed in the NEOWISE-R survey
• Observational signatures of outbursting protostars - I: From hydrodynamic simulations to observations
• The JCMT Transient Survey: An Extraordinary Submillimetre Flare in the T Tauri Binary System JW 566
• Discovery of a mid-infrared protostellar outburst of exceptional amplitude
• SPIRITS Catalog of Infrared Variables: Identification of Extremely Luminous Long Period Variables
• High Resolution Optical and NIR Spectra of HBC 722
• Spectral evolution and radial dust transport in the prototype young eruptive system EX Lup
• Re-appearance of McNeil's nebula (V1647 Orionis) and its outburst environment
• Orbital Migration of Protoplanets in a Marginally Gravitationally Unstable Disk
• YSO jets in the Galactic Plane from UWISH2: IV - Jets and outflows in Cygnus-X
• YSO jets in the Galactic Plane from UWISH2: III - Jets and Outflows in Cassiopeia and Auriga
• AGB interlopers in YSO catalogues hunted out by NEOWISE
• The outbursting protostar 2MASS~22352345+7517076 and its environment
• CO Outflow Survey of 68 Very Low Luminosity Objects: a Search for Proto-Brown Dwarf Candidates
• Classification Study of WISE Infrared Sources: Identification of Candidate Asymptotic Giant Branch Stars
• Spot modelling of periodic weak-line T Tauri stars observed by CoRoT in NGC 2264
• Interpretation of a Variable Reflection Nebula Associated with HBC 340 and HBC 341 in NGC 1333
• WISE Discovery of Mid-infrared Variability in Massive Young Stellar Objects
• WISE photometry of EXor sources and candidates
• The mid-infrared variability of the SDSS optical quasars

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• Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST. IV
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• The JCMT Transient Survey: Single Epoch Transients and Variability of Faint Sources
• WTP10aaauow: Discovery of a new FU Ori outburst towards the RCW49 star-forming region in NEOWISE data
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• Physical conditions for dust grain alignment in Class 0 protostellar cores II. The role of the radiation field in models aligning/disrupting dust grains
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