  We present new multi-broadband transit photometry of HD 189733b obtained at
the Wyoming Infrared Observatory. Using an ensemble of five-band Sloan filter
observations across multiple transits we have created an "ultra-low" resolution
transmission spectrum to discern the nature of the exoplanet atmosphere. The
observations were taken over three transit events and total 108 u', 120 g', 120
r', 110 i', and 116 z' images with an average exposure cadence of seven minutes
for an entire series. The analysis was performed with a Markov-Chain
Monte-Carlo method assisted by a Gaussian processes regression model. We find
the apparent planet radius to increase from 0.154 +0.000920-0.00096 R* at
z'-band to 0.157 +0.00074-0.00078 R* at u'-band. Whether this apparent radius
implies an enhanced Rayleigh scattering or clear or grey planet atmosphere is
highly dependent on stellar spot modeling assumptions, but our results are
consistent with the literature for HD 189733b. This set of observations
demonstrates the ability of our 2.3-m ground-based observatory to measure
atmospheres of large exoplanets.
