  We report observations of a stellar occultation by the classical Kuiper belt
object (50000) Quaoar occurred on 28 June 2019. A single-chord high-cadence (2
Hz) photometry dataset was obtained with the Tomo-e Gozen CMOS camera mounted
on the 1.05 m Schmidt telescope at Kiso Observatory. The obtained ingress and
egress data do not show any indication of atmospheric refraction and allow to
set new $1\sigma$ and $3\sigma$ upper limits of 6 and 16 nbar, respectively,
for the surface pressure of a pure methane atmosphere. These upper limits are
lower than the saturation vapor pressure of methane at Quaoar's expected mean
surface temperature ($T \sim 44$ K) and imply the absence of a $\sim$10
nbar-level global atmosphere formed by methane ice on Quaoar's surface.
