Trilithium torpedo

The trilithium torpedo is a superweapon developed by Dr. Tolian Soran. It uses trilithium -- a biproduct of the Federation's matter-antimatter power system -- to cause a near-instant collapse of any star. The collapse also produces an incredibly powerful subspace shockwave capable of destroying everything in that star system.

The only existing examples of the device were either used or destroyed on the launch pad, and all data on its design was lost with the destruction of the Klingon Bird of Prey on which it was carried.