2014, Kühnel, M., Müller, S., Kreykenbohm, I., Fürst, F., Pottschmidt, K., Rothschild, R.E., Caballero, I., Grinberg, V., Schönherr, G., Shrader, C., Klochkov, D., Staubert, R., Ferrigno, C., Torrejón, J.-M., Martínez-Núñez, S., Wilms, J.

In a former publication, we have analyzed the transient neutron star X-ray binary GRO J1008-57 using all available RXTE-, Swift-, and Suzaku-data. As we have found, the source's spectral components, i.e., a power-law with high exponential cutoff and a black-body, are strongly correlated with the hard X-ray flux (15-50 keV). We update the analytical description of these dependence, including a change in the photon index behaviour from a flat to a logarithmic function. The flux, where the change occurs, is consistent with the onset of the black-body emission. Thus, a change of the accretion state always occurs in GRO J1008-57 at a particular flux level.