  The processes that shape the extended atmospheres of red supergiants (RSGs),
heat their chromospheres, create molecular reservoirs, drive mass loss, and
create dust remain poorly understood. Betelgeuse's V-band "Great Dimming" event
of 2019 September /2020 February and its subsequent rapid brightening provides
a rare opportunity to study these phenomena. Two different explanations have
emerged to explain the dimming; new dust appeared in our line of sight
attenuating the photospheric light, or a large portion of the photosphere had
cooled. Here we present five years of Wing three-filter (A, B, and C band) TiO
and near-IR photometry obtained at the Wasatonic Observatory. These reveal that
parts of the photosphere had a mean effective temperature $(T_{\rm eff}$)
significantly lower than that found by (Levesque & Massey 2020). Synthetic
photometry from MARCS -model photospheres and spectra reveal that the V band,
TiO index, and C-band photometry, and previously reported 4000-6800 Angstrom
spectra can be quantitatively reproduced if there are multiple photospheric
components, as hinted at by VLT-SPHERE images (Montarges et al. 2020). If the
cooler component has $\Delta T_{\rm eff} \ge 250$ K cooler than 3650 K, then no
new dust is required to explain the available empirical constraints. A
coincidence of the dominant short- ($\sim 430$ day) and long-period ($\sim 5.8$
yr) V-band variations occurred near the time of deep minimum (Guinan et al.
2019). This is in tandem with the strong correlation of V mag and photospheric
radial velocities, recently reported by Dupree et al. (2020b). These suggest
that the cooling of a large fraction of the visible star has a dynamic origin
related to the photospheric motions, perhaps arising from pulsation or
large-scale convective motions.
