GRS1915+105 MERLIN

In Autumn 1997, triggered by the observation of a radio outburst with the Ryle Telescope, MERLIN was able to capture the early stages in the development of twin relativistic jets in GRS1915+105. Relativistic expansion, following a three times stronger radio flare, was first discovered with the VLA in 1994. During the 1997 outburst MERLIN was able to trace the development of the jets four times closer to the binary than did the VLA in 1994. The expansion rate derived from the sequence of MERLIN maps is similar to that in 1994. The inferred velocity in the rest frame of the binary is 0.92c to 0.98c, depending on the assumed distance for the source.
Fender (Amsterdam) Spencer, McKay, Garrington, Muxlow et al (Manchester) and Pooley (Cambridge)