Bibcode
Vida, K.; Turner, N. J.; Tóth, I.; Szing, A.; Szalai, N.; Szakáts, R.; Sárneczky, K.; Pál, A.; Moór, A.; Meszaros, Sz.; Marton, G.; Kun, M.; Kovács, T.; Kelemen, J.; Henning, Th.; Farkas, A.; Szegedi-Elek, E.; Carnerero, M. I.; Balog, Z.; Arévalo, M. J.; Acosta-Pulido, J. A.; Ábrahám, P.; Kóspál, Á.
Bibliographical reference
Astronomy and Astrophysics, Volume 551, id.A62, 12 pp.
Advertised on:
3
2013
Journal
Citations
26
Refereed citations
25
Description
Context. V2492 Cyg is a young eruptive star that went into outburst in
2010. The near-infrared color changes observed since the outburst peak
suggest that the source belongs to a newly defined sub-class of young
eruptive stars, where time-dependent accretion and variable
line-of-sight extinction play a combined role in the flux changes. Aims: In order to learn about the origin of the light variations and
to explore the circumstellar and interstellar environment of V2492 Cyg,
we monitored the source at ten different wavelengths, between 0.55 μm
and 2.2 μm from the ground and between 3.6 μm and 160 μm from
space. Methods: We analyze the light curves and study the
color-color diagrams via comparison with the standard reddening path. We
examine the structure of the molecular cloud hosting V2492 Cyg by
computing temperature and optical depth maps from the far-infrared data.
Results: We find that the shapes of the light curves at different
wavelengths are strictly self-similar and that the observed variability
is related to a single physical process, most likely variable
extinction. We suggest that the central source is episodically occulted
by a dense dust cloud in the inner disk and, based on the invariability
of the far-infrared fluxes, we propose that it is a long-lived rather
than a transient structure. In some respects, V2492 Cyg can be regarded
as a young, embedded analog of UX Orionis-type stars.
Conclusions: The example of V2492 Cyg demonstrates that the light
variations of young eruptive stars are not exclusively related to
changing accretion. The variability provided information on an
azimuthally asymmetric structural element in the inner disk. Such an
asymmetric density distribution in the terrestrial zone may also have
consequences for the initial conditions of planet formation.
This work is based on observations made with the Herschel Space
Observatory and with the Spitzer Space Telescope. Herschel is an ESA
space observatory with science instruments provided by European-led
Principal Investigator consortia and with important participation from
NASA. Spitzer is operated by the Jet Propulsion Laboratory, California
Institute of Technology under a contract with NASA.Tables 1 and 2 are
available in electronic form at http://www.aanda.org
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