An infrared view of the EXor variables: on the case of V1118 ORI

Abstract

We investigate the relationship between the IR observed properties of the EXor variables and the mechanisms active during their evolutionary stage. To this aim, we have constructed a catalog of all the IR (1-100 micron) photometric and spectroscopic observations appearing during the last 30 years in the literature. New results of our monitoring program based on near- and mid-IR photometry and near-IR spectroscopy and polarimetry of one object (V1118 Ori) are presented, complementing those given in a previous paper and related to a different activity period. Our catalog indicates how the database accumulated so far is inadequate for any statistical study of the EXor events. Nevertheless, all the observational evidence can be interpreted into a coherent scheme. The sources that present the largest brightness variations tend to become bluer while brightening. The scenario of disk accretion based on viscous friction between particles agrees with the observations. The new results on V1118 Ori confirm such a general view. The striking novelty is represented by a near-IR spectrum of V1118 Ori taken 1 yr after the last monitored outburst: any emission line previously detected has now totally disappeared at our sensitivity. For the same source, mid-IR photometry is provided here for the first time and allows us to construct a meaningful SED. The first polarimetric data show that V1118 Ori is intrinsically polarized and its spotted, magnetized surface becomes recognizable during the less active phases.

23 pages. To be published to Astrophysical Journal

References in corpus (3)

• A Survey and Analysis of Spitzer Infrared Spectrograph Spectra of T Tauri Stars in Taurus
• Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy
• Evidence for T Tauri-like emission in the EXor V1118 Ori from near-IR and X-ray data

Cited by in corpus (23)

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• Near Infrared Spectroscopic Monitoring of EXor variables: First Results
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• The 2008 outburst of EX Lup - silicate crystals in motion
• PTF10nvg: An Outbursting Class I Protostar in the Pelican/North American Nebula
• GIARPS High-resolution Observations of T Tauri stars (GHOsT). II. Connecting atomic and molecular winds in protoplanetary disks
• A multi-wavelength study of the young star V1118 Orionis in outburst
• Extreme infrared variables from UKIDSS - II. an end-of-survey catalogue of eruptive YSOs and unusual stars
• The VVV Templates Project. Towards an Automated Classification of VVV Light-Curves. I. Building a database of stellar variability in the near-infrared
• On the mid-IR variability of candidate eruptive variables (EXors): a comparison between Spitzer and WISE data
• Simultaneous monitoring of the photometric and polarimetric activity of the young star PV Cep in the optical/near-infrared bands
• EXORCISM: a spectroscopic survey of young eruptive variables (EXor and candidates)
• ALMA Observations of Young Eruptive Stars: continuum disk sizes and molecular outflows
• On the 2015 outburst of the EXor variable star V1118 Ori
• Pre-Main Sequence variables in the VMR-D : identification of T Tauri-like accreting protostars through Spitzer-IRAC variability
• Interpreting the simultaneous variability of near-IR continuum and line emission in young stellar objects
• Do subsequent outbursts of the same EXor source present similar features?
• A long-lasting quiescence phase of the eruptive variable V1118 Ori
• WISE photometry of EXor sources and candidates
• Investigating the past history of EXors: the cases of V1118 Ori, V1143 Ori, and NY Ori
• The Enigma of Gaia18cjb: a Rare Hybrid of FUor and EXor?
• First X-ray dectection of the young variable V1180 Cas
• Automatic Detection of Accretion Bursts in Young Stellar Objects: a New Algorithm for Long--Term Sky Surveys