ISO-Cha I 192: A New Embedded Eruptive Variable in the Chamaeleon I Dark Cloud

We report the detection of an increase of about 2 mag in the 2.2 mm brightness of ISO-Cha I 192, a class I low-mass stellar object thought to be driving a bipolar CO outflow in the Chamaeleon I cloud. This substantial brightness change has taken place during less than 3 yr, from 1996 March to 1999 April. An elongated infrared reflection nebula of size ~530 AU is seen originating from the star in the direction of the CO bipolar outflow. The historic infrared properties of this young stellar object are examined in order to substantiate the hypothesis that this object is an FU Ori- or EX Lup-type system. Combining our new ground-based near- and mid-infrared photometry with Spitzer IRAC and MIPS broadband fluxes supplemented by published recent spectrophotometry, the spectral energy distribution of this source was constructed. We explored the plausibility of a 'standard' configuration of infalling envelope + disk + central source for this object by fitting a two-dimensional radiative transfer code that includes the contributions of each of these components.