Spitzer Space Telescope - General Observer Proposal #80165


Disk tomography during the outburst of two new young eruptive stars

Principal Investigator: Peter Abraham
           Institution: Konkoly Observatory

     Technical Contact: Peter Abraham, Konkoly Observatory

Co-Investigators: 
Agnes Kospal, Leiden Observatory                                      
Attila Moor, Konkoly Observatory                                      

Science Category: young stellar objects 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 1.8 

Abstract:
Most young stars are variable, and not only at optical, but also at infrared
wavelengths. Our group had proposed a new method to interpret such light
variations using a tomographic technique. It is based on analyzing the time
variations of the integrated flux of a shrinking illuminated disk area during
the fading. We also suggested that rearrangement in the density structure of the
inner disk - mainly due to evaporation/condensation of dust particles in the
outburst heat - can be seen in the multicolor light curves. The outbursts of two
so-far unknown young eruptive stars in Cygnus in 2010 August offer the
long-waited opportunity to perform a proof-of-concept analysis of our proposed
methods to investigate disk tomography and dynamics. Here we propose to conduct
a multi-epoch survey of two young eruptive star during their outburst with
Spitzer/IRAC. We will obtain 3.6 and 4.5 um images at 9 epochs, and the data
will be supplemented by simultaneous ground-based optical and near-infrared
photometry. The flux and color variations of HBC 722 will be interpreted using
the new method of disk tomography, while the corresponding data on VSX
J205126.1+440523 will be interpreted in terms of the sum of variable
illumination and time variable density structure of the inner disk/envelope.
Our study may demonstrate that variability, in particular the wavelength
dependence of flux variations over the whole infrared domain, provides an
extremely powerful ?extra dimension? of information, in addition to space and
wavelength.