Temporal and spectral analysis of 4U 1907+09 observed by BeppoSAX

We report on temporal and spectral analysis performed on 4U 1907 + 09 obser ved by BeppoSAX. We found a new measurement of the pulse period, that indic ates that the source is still spinning-down at a rate of (P) over dot = +0. 243 s/yr. The pulse profile is double peaked in the soft X-ray range, while the first peak disappears in the hard range (above 20 keV). The pulse phas e averaged spectrum shows the presence of two absorption features at simila r to 20 and 40 keV, tentatively identified with the fundamental and the sec ond harmonic cyclotron lines respectively. The pulse phase resolved analysi s is also reported. The second harmonic is clearly visible at the phases of the hard peak and the minimum.