Core mass remaining at the time when the triple systems have their last close triple encounter and the binary becomes bound, resulting in either a bound stable (red) or bound unstable (green) system or a disrupted system (gray). As the figure illustrates, stable triple systems are formed only in the presence of a cloud core. The few stable systems that are indicated as having been formed with near-zero gas mass are misclassified by the stability criterion, they are unstable and will eventually disrupt.