  We present the first detailed spectral and timing analysis of the High Mass
X-ray Binary (HMXB) 4U 1909+07 with INTEGRAL and RXTE. 4U 1909+07 is detected
with an average of 2.4cps in ISGRI, but shows flares up to ~50cps. The system
shows a pulse period of 605s, but we found that the period changes erratically
around this value. The pulse profile is extremely energy dependent: while it
shows a double peaked structure at low energies, the secondary pulse decreases
rapidly with increasing energy and above 20keV only the primary pulse is
visible. This evolution is consistent between PCA, HEXTE and ISGRI. We find
that the phase averaged spectrum can be well fitted with a photoabsorbed power
law with a cutoff at high energies and a blackbody component. To investigate
the peculiar pulse profile, we performed phase resolved spectral analysis. We
find that a change in the cutoff energy is required to fit the changing
spectrum of the different pulse phases.
