Observed P Cygni
profiles in two hot
stars:
z
Pup
(O4,
10
6
L
sun
) and
t
Sco
(B0 V, 50,000 L
sun
)
Steady-state
theory is very
successful
at
explaining the
time-average
properties of hot-
star winds
OB stars have massive, radiation-driven winds