Sarnus was a world in the Chiloon Rift. In 45 ABY, Lando Calrissian had established a refinery on the world to mine the plentiful asteroids present in the rift.
Han Solo suffered an assassination attempt at Lando's refinery. Planned by Marvid and Craitheus Qreph, the attempt failed, but left more than 30,000 dead beings.