  We have analysed the direct photon data obtained by the WA80 collaboration in
200 A GeV S+Au collision at CERN SPS, in a one dimensional hydrodynamical
model. Two scenario was considered: (i) formation of quark-gluon plasma and
(ii) formation of hot hadronic gas. For both the scenario, ideal as well as
extremely viscous fluid was considered. It was found that direct photon yield
from QGP is not affected much whether the fluid is treated as ideal or
extremely viscous. The yield however differ substantially if hadron gas is
produced. Both the scenario do not give satisfactory description of the data.
