M25 Limit

The distance from a body of mass beyond which the Hyperspace Drive can be safely operated. A rough rule of thumb for most cases is the M25 exists at around the 'g' of the body in Astronomical Units. So the star Sol, with a gravity well of around 26g has an M25 Limit some 26 AU from it. The rule of thumb breaks down for very high gravitic masses (such as black holes) and very small microgravities (such as asteroids), but this is sufficient for most navigational purposes.