The Hanoli system was a star system.
In the mid-23rd century, a subspace rupture was reported in the system. Some time therafter, a Vulcan science mission attempted to seal the rupture with a pulse wave torpedo, but instead caused the rupture to expand exponentially. The entire star system, as well as the Vulcans, were wiped out after which the rupture reached its critical mass and imploded, destroying itself. By the 24th century, its former location was no longer widely known among Starfleet officers. (DS9: "If Wishes Were Horses")