  Based on our new NuSTAR X-ray telescope data, we rule out any cyclotron line
up to 60 keV in the spectra of the high mass X-ray binary 4U2206+54. In
particular, we do not find any evidence of the previously claimed line around
30 keV, independently of the source flux, along the spin pulse. The spin period
has increased significantly, since the last observation, up to $5750\pm10$ s,
confirming the rapid spin down rate $\dot \nu=-1.8\times 10^{-14}$~Hz s$^{-1}$.
This behaviour might be explained by the presence of a strongly magnetized
neutron star ($B_{\rm s}>$ several times $10^{13}$ G) accreting from the slow
wind of its main sequence O9.5 companion.

High Energy Astrophysical Phenomena