An increase in the X-ray flux from Centaurus A.

Observations of the 0.5-7.5 keV X-ray spectrum of Centaurus A (Cen A) were made by the Copernicus satellite in June, 1973. The luminosity of the source in the 2.5-7.5 keV range is found to have increased by a factor of 4 in the two years since the last reported observation by the Uhuru satellite. The value of the absorbing gas column density and the power law index are consistent with those determined by Uhuru. The luminosity increase indicates that the emitting region responsible for it is only a few light years in extent, confirming that the X-ray source is the nucleus of Cen A.