The Catastrophe was an event in the history of the Vostigye peoples.

While the Vostigye were at a primitive level of spaceflight, a white dwarf's gravitational pull caused intense geological upheaval on the Birthworld. In response, the Vostigye quickly developed the technology to survive in space, despite not knowing if they could actually build self-sustaining biospheres. (VOY - Myriad Universes novel: Places of Exile)