Identification of the soft X-ray source H1011-47 (= E1013-477): a newmagnetic variable?
Reichert, G. A.; Bowyer, S.; Córdova, F. A.; Mason, K. O.; Murdin, P.; Middleditch, J.; Clark, D.
United Kingdom
Abstract
A variable blue emission-line star is determined to be the probable counterpart of the HEAO-1 soft X-ray source H1011-47 on the basis of an improved position derived with the Einstein satellite. The star is found to vary between magnitudes of 16.7 and 17.7 on a time scale of approximately 100 minutes and by as much as 0.6 magnitude on a time scale of a few minutes. The spectrum shows strong, broad optical emission lines of hydrogen, He I, He II, and Ca II and strong ultraviolet emission lines of C IV and Si IV. These characteristics indicate that the star most probably belongs to the AM Her class of magnetic cataclysmic binary. A comparison of the HEAO-1 and Einstein fluxes for the source indicates that it is variable in the long term by at least a factor of ten. Attention is also given to two other faint X-ray sources observed in or near the HEAO-1 error box. One is identified with an 8th magnitude star, the other with a quasar having a redshift z of 0.42.