The disappearing act: A dusty wind eclipsing RW Aur

Abstract

RW Aur is a young binary star that experienced a deep dimming in 2010-11 in component A and a second even deeper dimming from summer 2014 to summer 2016. We present new unresolved multi-band photometry during the 2014-16 eclipse, new emission line spectroscopy before and during the dimming, archive infrared photometry between 2014-15, as well as an overview of literature data. Spectral observations were carried out with the Fibre-fed RObotic Dual-beam Optical Spectrograph on the Liverpool Telescope. Photometric monitoring was done with the Las Cumbres Observatory Global Telescope Network and James Gregory Telescope. Our photometry shows that RW Aur dropped in brightness to R = 12.5 in March 2016. In addition to the long-term dimming trend, RW Aur is variable on time scales as short as hours. The short-term variation is most likely due to an unstable accretion flow. This, combined with the presence of accretion-related emission lines in the spectra suggest that accretion flows in the binary system are at least partially visible during the eclipse. The equivalent width of [O I] increases by a factor of ten in 2014, coinciding with the dimming event, confirming previous reports. The blue-shifted part of the $H\alpha$ profile is suppressed during the eclipse. In combination with the increase in mid-infrared brightness during the eclipse reported in the literature and seen in WISE archival data, and constraints on the geometry of the disk around RW Aur A we arrive at the conclusion that the obscuring screen is part of a wind emanating from the inner disk.

arXiv comment11 pages, 9 figures

References in corpus (21)

• The USNO-B Catalog
• Las Cumbres Observatory Global Telescope Network
• Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science
• Initial Performance of the NEOWISE Reactivation Mission
• 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
• On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga
• The T Tauri Phase Down to Nearly Planetary Masses: Echelle Spectra of 82 Very Low Mass Stars and Brown Dwarfs
• Temperaments of young stars: Rapid mass-accretion rate changes in T Tauri and Herbig Ae stars
• CSI 2264: Probing the inner disks of AA Tau-like systems in NGC 2264
• Non-axisymmetric accretion on the classical TTS RW Aur A
• A tidal encounter caught in the act: modelling a star-disc fly-by in the young RW Aurigae system
• Proper motions and velocity asymmetries in the RW Aur jet
• HST/STIS observations of the RW Aurigae bipolar jet: mapping the physical parameters close to the source
• A fully automated data reduction pipeline for the FRODOSpec integral field spectrograph
• Constraining the Sub-AU-Scale Distribution of Hydrogen and Carbon Monoxide Gas around Young Stars with the Keck Interferometer
• Occultation of the T Tauri Star RW Aurigae A by its Tidally Disrupted Disk
• Hot spots and a clumpy disk: Variability of brown dwarfs and stars in the young Sigma Ori cluster
• Another deep dimming of the classical T Tauri star RW Aur A
• Recurring Occultations of RW Aurigae by Coagulated Dust in the Tidally Disrupted Circumstellar Disk
• Stable and Unstable Regimes of Mass Accretion onto RW Aur A
• The nature of the 2014-2015 dim state of RW Aur revealed by X-ray, optical, and NIR observations

Cited by in corpus (21)

• Quantifying Variability of YSOs in the Mid-IR Over Six Years with NEOWISE
• Multiple Stellar Fly-Bys Sculpting the Circumstellar Architecture in RW Aurigae
• Determining the recurrence timescale of long-lasting YSO outbursts
• Violent environment of the inner disk of RW Aur A probed by the 2010 and 2015 dimming events
• Analysis of colour and polarimetric variability of RW Aur A in 2010-2018
• Time-resolved photometry of the young dipper RX J1604.3-2130A: Unveiling the structure and mass transport through the innermost disk
• Exploring the dimming event of RW Aur A through multi-epoch VLT/X-Shooter spectroscopy
• Multi-epoch monitoring of the AA Tau like star V354 Mon - Indications for a low gas-to-dust ratio in the inner disk warp
• A survey for variable young stars with small telescopes: First results from HOYS-CAPS
• Optical dimming of RW Aur associated with an iron rich corona and exceptionally high absorbing column density
• Time-Variable Jet Ejections from RW Aur A, RY Tau and DG Tau
• VVV-WIT-08: the giant star that blinked
• The dimming of RW Auriga. Is dust accretion preceding an outburst?
• The jet of the young star RW Aur A and related problems
• A survey for variable young stars with small telescopes: II -- Mapping a protoplanetary disk with stable structures at 0.15 AU
• Photometric and Spectroscopic monitoring of YSOs in nearby star forming regions. I. Eruptive YSOs
• RW Aur B: a modest UX Ori type companion of the famous primary
• RW Aur A : SpeX Spectral Evidence for Differentiated Planetesimal Formation, Migration and Destruction in an 3 Myr Old Excited CTTS System
• The weakening outburst of the young eruptive star V582 Aur
• Clumpy dust rings around non-accreting young stars
• Warps survive beyond fly-by encounters in protoplanetary disks. RW Aur A as a case study