X-ray Nova flares

In order to find out the physical nature of Galactic X-ray sources, data on the variability of 24 sources during 1964-1971 have been investigated. The fluxes of 9 sources are found to be increasing to the maximum value (for several months) and then slowly decreasing (for 3 years). These 9 sources have been related to the class of X-ray Novae. The X-ray Novae synthetic light curve has been drawn from data of the fluxes of 9 discovered Novae. Assumptions have been made on the physical nature of the X-ray Novae. Between the flares the X-ray Novae may be weak X-ray sources with a luminosity of about 1034erg s-1. During the flares the luminosity increases to about 1038 erg s-1. The number of X-ray sources in the Galaxy is about 103-104. The object of the optical identification may be a dwarf star of no earlier spectral class than F. (Auth.)