A star system with a Federation observatory, whose sun was collapsed by Tolian Soran in 2371 as the first step in steering the Nexus towards him.
The Amargosa system is home to the Amargosa observatory, a Federation station studying the system's star. In Star Trek Generations, set in 2371, the USS Enterprise-D answers a distress call and finds the observatory wrecked by Romulans who were hunting for stolen trilithium.
One of the survivors, the El-Aurian scientist Tolian Soran, has been using the station to build a trilithium weapon. He fires a probe into the Amargosa star, halting its fusion and causing it to collapse. The resulting shock wave destroys the observatory, and Soran escapes with Geordi La Forge aboard a Klingon Bird-of-Prey belonging to the Duras sisters.
Data and Picard later work out the purpose. Removing the star alters gravity across the sector and shifts the course of the Nexus energy ribbon.