  The origin of dust in the early Universe has been the subject of considerable
debate. Core-collapse supernovae (ccSNe), which occur several million years
after their massive progenitors form, could be a major source of that dust, as
in the local universe several ccSNe have been observed to be copious dust
producers. Here we report nine near-infrared (0.8 - 2.5 micron) spectra of the
Type II-P SN 2017eaw in NGC 6946, spanning the time interval 22 - 205 days
after discovery. The specta show the onset of CO formation and continuum
emission at wavelengths greater than 2.1 micron from newly-formed hot dust, in
addition to numerous lines of hydrogen and metals, which reveal the change in
ionization as the density of much of the ejecta decreases. The observed CO
masses estimated from an LTE model are typically 10^{-4} Msun during days 124 -
205, but could be an order of magnitude larger if non-LTE conditions are
present in the emitting region. The timing of the appearance of CO is
remarkably consistent with chemically controlled dust models of Sarangi &
Cherchneff.
