X-ray observations of H1908+050 (=SS433?)

The X-ray source H1908+50 (=4U1908+05=A1909+4) was observed for three 6 day periods in 1977 and 1978 with the HEAO A-2 experiment. The unusual emission line object and variable radio source SS433 was suggested as the optical counterpart. The X-ray of the source varied by a factor of about 2 on a time scale of 6 months, and the spectrum of the object is consistent with either a power law of photon index of 2.1 or with 14.3 keV thermal bremsstrahlung emission with about 575 eV equivalent width iron line. These X-ray characteristics argue against the source being extragalactic. The measurements are consistent with emission from a white dwarf, but are also similar to the X-ray emission sometimes seen from Cir X-1. A search was made for X-ray emission from similar radio sources.