VSOP observations of the X-ray binary LSI+61303

Abstract

The HALCA spacecraft in combination with a large array of ground radio telescopes has been used to obtain multi-epoch images of a radio outburst of the radio emitting, X-ray binary star LSI+61o303. Preliminary results from two 6-hour segments separated by 28.6 hours are presented. The images reveal an apparently stationary pattern of symmetric emission extending about 2 mas on either side of a central source. The extended emission is reminiscent of the precessing radio jets seen in SS433. The central source is observed to expand at a rate of 0.2 mas/day. At the distance of LSI+61o303, this corresponds to about700 km s^-1.