  Studies of some bright, super-Eddington transient pulsars show a negative
correlation between the energy of the cyclotron resonance scattering feature
(CRSF) and the bolometric luminosity. For Her X-1, using repeated RXTE
observations during 1996-2005, the inverse dependence was found: the energy of
the cyclotron line increases as the luminosity increases. The X-ray flux
measured by the RXTE/ASM (2-10 keV) has been assumed to represent the
luminosity - more precisely: the maximum X-ray flux reached during the
respective 35 d Main-On. Here, we question whether the ASM flux is really an
accurate measure of the bolometric luminosity of the source. We redetermined
the energy of the cyclotron line and performed spectral fits using the combined
data from the PCA (3.5-60 keV) and HEXTE (20-75 keV) instruments on RXTE of the
same 35 d cycles as used in the original work to determine the bolometric flux
from those spectra. We confirm the result of the original analysis that the
cyclotron line energy changes by ~7% for a change in flux by a factor of two.
