Gas from the surface of the visible star is accreted onto the dark companion, which appears to be a stellar black hole with several times the mass of the Sun.

Along with GRS 1915+105, GRO J1655−40 is one of at least two galactic "microquasars" that may provide a link between the supermassive black holes generally believed to power extragalactic quasars and more local accreting black hole systems.

GRO J1655−40 and its companion are moving through the Milky Way at around 112 km/s (250,000 miles per hour), in a galactic orbit that depends on its exact distance, but is mostly interior to the "Solar circle", d~8,500 pc, and within 150 pc (~500 ly) of the galactic plane.

Such explosions often seem to leave the remnant system moving through the galaxy with unusually high speed.

This can be easily modeled assuming propagation of an oscillating shock wave: steadily going closer to the black hole due to rise in the Keplerian component rate in the rising phase and going away from the black hole as viscosity is withdrawn in the declining phase.