An expensive specialized warhead for Lance Torpedoes that uses a fusion explosion to power a reaction similar to that in a tractor beam emitter, and produce a very powerful asymmetric gravity field for a brief instant. For that instant, any ship within the area of the effect will experience a rapidly changing asymmetric gravity field and will be torn apart by its own weight. A development of the same principle behind Graviton Cannons.
In the Battle of St. Michael's Star during the Ascension War, the Imperial Navy used graviton torpedoes as an effective area weapon against an enemy Earth Fleet starfighter screen, creating huge gaps in the formation that the Imperial fighers immediately (albeit unsucessfully) tried to exploit.
This is a concept we borrowed from one Martin came up with for a Star Trek fanfic he never got around to writing back in High School. In turn, he was inspired by the "Gravitic Mines" seen in the Star Trek tie-in novel "The Kobayashi Maru" by Julia Ecklar.