  Our Spitzer IRS observation of the infrared companion Glass Ib revealed fine
structure emission with high ionization ([NeIII]/[NeII]=2.1 and
[SIV]/[SIII]=0.6) that indicates the gas is likely illuminated by hard
radiation. While models suggest extreme ultraviolet radiation could be present
in T Tauri stars (Hollenbach & Gorti 2009 and references therein), this is the
first detection of [SIV] and such a high [NeIII]/[NeII] ratio in a young star.
We also find that Glass Ib displays the molecules HCN, CO2, and H2O in
emission. Here we investigate the Glass I binary system and consider possible
mechanisms that may have caused the high ionization, whether from an outflow or
disk irradiation. We also model the spectral energy distributions of Glass Ia
and Ib to test if the system is a young member of the Chameleon I star-forming
region, and consider other possible classifications for the system. We find
Glass Ib is highly variable, showing changes in continuum strength and emission
features at optical, near-infrared, and mid-infrared wavelengths. The optical
light curve indicates that a central stellar component in Glass Ib became
entirely visible for 2.5 years beginning in mid-2002, and that possibly
displayed periodic variability with repeated, short-period dimming during that
time. As the fine structure emission was not detected in observations before or
after our Spitzer IRS observation, we explore whether the variable nature of
Glass Ib is related to the gas being highly ionized, possibly due to variable
accretion or an X-ray flare.

Solar and Stellar Astrophysics