We present a reanalysis of the outburst radial velocity data for X-Ray Nova Scorpii 1994 .
Using a model based on X-ray heating of the secondary star we suggest a more realistic treatment of the radial velocity data .
Solutions are obtained in the ( K _ { 2 } ,q ) plane which , when combined with the published value for the binary mass ratio and inclination , constrain the mass of the black hole to within the region 4.1 < M _ { 1 } < 6.6 M _ { \odot } ( 90 per cent confidence ) , which is significantly lower than the value obtained by Orosz & Bailyn ( 1997 ) .
This reduced lower bound for the black hole mass together with the high space velocity of the system is consistent with the idea that it was formed by the post-supernova collapse of a neutron star .