  The rotational lightcurves of the Pluto-Charon system were previously
believed to be solely attributed to their surfaces. However, a proposed
scenario of haze cooling \citep{2017Natur.551..352Z} suggests that the
atmospheric haze of Pluto could significantly contribute to mid-infrared
emission, which calls for a revisit of previous analyses. In this study, we
employ a Bayesian retrieval approach to constrain the haze emission from the
rotational lightcurves of the Pluto-Charon system. The lightcurves were
observed by the Spitzer and Herschel telescopes at 24 and 70 $\mu$m, and were
combined with the latest surface albedo maps of Pluto and Charon from the New
Horizons spacecraft. Our results show that including the haze emission is
consistent with all current observations, with the best-fit haze flux around
1.63 mJy. This is in agreement with the composition of Titan-like tholins.
However, the ``surface only" scenario, which excludes the haze contribution,
can still explain the observations. We conclude that the current data at 24
$\mu$m cannot constrain Pluto's haze emission due to the degeneracy with
Charon's surface emission. Regardless, some surface properties of Pluto are
well constrained by the shape of the lightcurves, with a thermal inertia of
approximately 8--10 MKS and a relatively low CH$_4$ emissivity of 0.3--0.5. We
suggest that observations by the JWST telescope at 18 $\mu$m, which can resolve
Pluto from Charon, could directly probe the haze emission of Pluto due to the
low surface emission at that wavelength.
