Spectral energy distributions (SED) of the system IGR J00291+5934 in two different epochs: phase 0.2 (red sqares) and phase 0.9 (blue dots). Phase 0.2 corresponds to a strong flare activity for the system. The fits of the two SEDs with a power law are shown (dashed and dotted lines, phase 0.2 and 0.9, respectively). Opposite behaviours can be observed (α = 0.31 ± 0.35 and α = −1.06 ± 0.35, respectively). All the points are corrected for reddening, the parameters of which are reported in Table 1.