Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2B061

Search for structural changes in T Tauri disks via optical-infrared variability

Ábrahám, Péter (Konkoly Observatory, Hungary)
Kóspál, Ágnes (European Space Agency, The Netherlands)
Curé, Michel (Universidad de Valparaiso, Chile)
Grady, Carol (NASA Goddard Space Flight Center, USA)
Henning, Thomas (Max-Planck-Institut für Astronomie, Germany)
Kun, Mária (Konkoly Observatory, Hungary)
Meyer, Michael (ETH Zürich, Switzerland)
Moór, Attila (Konkoly Observatory, Hungary)
Prusti, Timo (European Space Agency, The Netherlands)

Abstract:
Time domain astronomy is one of the frontier discovery areas of the next decade. Exploration of the time domain as the fourth dimension in circumstellar disk studies will potentially have a very high impact on many aspects of our knowledge on the formation of stars and planets. Here we present an optical-to-mid-infrared coordinated ground-based and Spitzer photometric monitoring study of nine low-mass young stars in the Chamaeleon I star forming region. We found that (1) all sources exhibit variability, and the flux changes observed at different filters are correlated; (2) in a group of four stars the amplitude of the variability is decreasing with wavelength; (3) in the other systems the amplitude of variability is high at optical wavelengths, exhibits a minimum around the J-band and increases again towards the mid-infrared domain. We speculate that in the second group the inner disk has a time-variable component which is well illuminated by the star and which casts a variable shadow onto the outer disk. The results are followed-up by a coordinated optical-to-far-IR 4-epoch survey carried out by SMARTS/ANDICAM, VLT/ISAAC and the Herschel Space Observatory.

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