Amargosa was the primary of the Amargosa system, studied by a Federation observatory where Dr. Tolian Soran developed his trilithium weapon. From the observatory, Soran launched the weapon into Amargosa in 2371 and collapsed the star, producing a level-12 shock wave that destroyed everything in the system.
The collapse of Amargosa had several repercussions in its sector of space. These effects included an increase in gamma emissions of .05% and a change in the ambient magnetic field. The most impostant effect was that gravitational forces were altered, forcing the USS Bozeman to make a minor course correction. The same forces altered the flight path of the Nexus ribbon as Soran had planned, as part of his attempt to bring the ribbon to Veridian III. (Star Trek Generations)