EX Lupi in quiescence

N. Sipos, P. Ábrahám, J. Acosta-Pulido, A. Juhász, Á Kóspál, M. Kun, A. Moór, J. Setiawan

Research output: Article

34 Citations (Scopus)

Abstract

Aims. EXLupi is the prototype of EXors, a subclass of low-mass pre-main sequence stars whose episodic eruptions are attributed to temporarily increased accretion. In quiescence the optical and near-infrared properties of EXLup cannot be distinguished from those of normal T Tau stars. Here we investigate whether it is the circumstellar disk structure that makes EXLup an atypical Class II object. During outburst the disk might undergo structural changes. Our characterization of the quiescent disk is intended to serve as a reference for studying the physical changes related to one of EXLupi's strongest known eruptions in 2008 Jan-Sep. Methods.We searched the literature for photometric and spectroscopic observations including ground-based, IRAS, ISO, and Spitzer data. After constructing the optical-infrared spectral energy distribution (SED), we compared it with the typical SEDs of other young stellar objects and modeled it using the Monte Carlo radiative transfer code RADMC. We determined the mineralogical composition of the 10 ìm silicate emission feature and also gave a description of the optical and near-infrared spectra. Results. The SED is similar to that of a typical T Tauri star in most aspects, though EXLup emits higher flux above 7 μm. The quiescent phase data suggest low-level variability in the optical-mid-infrared domain. By integrating the optical and infrared fluxes, we derived a bolometric luminosity of 0.7 L. The 10 ìm silicate profile could be fitted by a mixture consisting of amorphous silicates, but no crystalline silicates were found. A modestly flaring disk model with a total mass of 0.025 M and an outer radius of 150AU was able to reproduce the observed SED. The derived inner radius of 0.2AU is larger than the sublimation radius, and this inner gap sets EXLup apart from typical T Tauri stars.

Original languageEnglish
Pages (from-to)881-889
Number of pages9
JournalAstronomy and Astrophysics
Volume507
Issue number2
DOIs
Publication statusPublished - nov. 4 2009

Fingerprint

silicates
silicate
spectral energy distribution
T Tauri stars
volcanic eruptions
radii
near infrared
volcanic eruption
energy
pre-main sequence stars
sublimation
Infrared Astronomy Satellite
structural change
outburst
radiative transfer
infrared spectra
accretion
luminosity
prototypes
stars

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Sipos, N., Ábrahám, P., Acosta-Pulido, J., Juhász, A., Kóspál, Á., Kun, M., ... Setiawan, J. (2009). EX Lupi in quiescence. Astronomy and Astrophysics, 507(2), 881-889. https://doi.org/10.1051/0004-6361/200911641

EX Lupi in quiescence. / Sipos, N.; Ábrahám, P.; Acosta-Pulido, J.; Juhász, A.; Kóspál, Á; Kun, M.; Moór, A.; Setiawan, J.

In: Astronomy and Astrophysics, Vol. 507, No. 2, 04.11.2009, p. 881-889.

Research output: Article

Sipos, N, Ábrahám, P, Acosta-Pulido, J, Juhász, A, Kóspál, Á, Kun, M, Moór, A & Setiawan, J 2009, 'EX Lupi in quiescence', Astronomy and Astrophysics, vol. 507, no. 2, pp. 881-889. https://doi.org/10.1051/0004-6361/200911641
Sipos N, Ábrahám P, Acosta-Pulido J, Juhász A, Kóspál Á, Kun M et al. EX Lupi in quiescence. Astronomy and Astrophysics. 2009 nov. 4;507(2):881-889. https://doi.org/10.1051/0004-6361/200911641
Sipos, N. ; Ábrahám, P. ; Acosta-Pulido, J. ; Juhász, A. ; Kóspál, Á ; Kun, M. ; Moór, A. ; Setiawan, J. / EX Lupi in quiescence. In: Astronomy and Astrophysics. 2009 ; Vol. 507, No. 2. pp. 881-889.
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AU - Juhász, A.

AU - Kóspál, Á

AU - Kun, M.

AU - Moór, A.

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AB - Aims. EXLupi is the prototype of EXors, a subclass of low-mass pre-main sequence stars whose episodic eruptions are attributed to temporarily increased accretion. In quiescence the optical and near-infrared properties of EXLup cannot be distinguished from those of normal T Tau stars. Here we investigate whether it is the circumstellar disk structure that makes EXLup an atypical Class II object. During outburst the disk might undergo structural changes. Our characterization of the quiescent disk is intended to serve as a reference for studying the physical changes related to one of EXLupi's strongest known eruptions in 2008 Jan-Sep. Methods.We searched the literature for photometric and spectroscopic observations including ground-based, IRAS, ISO, and Spitzer data. After constructing the optical-infrared spectral energy distribution (SED), we compared it with the typical SEDs of other young stellar objects and modeled it using the Monte Carlo radiative transfer code RADMC. We determined the mineralogical composition of the 10 ìm silicate emission feature and also gave a description of the optical and near-infrared spectra. Results. The SED is similar to that of a typical T Tauri star in most aspects, though EXLup emits higher flux above 7 μm. The quiescent phase data suggest low-level variability in the optical-mid-infrared domain. By integrating the optical and infrared fluxes, we derived a bolometric luminosity of 0.7 L. The 10 ìm silicate profile could be fitted by a mixture consisting of amorphous silicates, but no crystalline silicates were found. A modestly flaring disk model with a total mass of 0.025 M and an outer radius of 150AU was able to reproduce the observed SED. The derived inner radius of 0.2AU is larger than the sublimation radius, and this inner gap sets EXLup apart from typical T Tauri stars.

KW - Infrared: stars

KW - Stars: circumstellar matter

KW - Stars: formation

KW - Stars: individual: EX Lup

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