I think we may have touched indirectly on this before, but my memory's fuzzy on details.
A planet has a region in which it influences the transition to jump space, making it risky to jump when too close: the 100-diameter limit. How risky varies from game variant to game variant, but the 100-diameter bit's pretty consistent, as far as I know.
That influence does not seem to be related to gravity. A tiny Size-1 world has a 100-diameter limit, a big Size-A has a 100 diameter limit, even though gravity out at the 100 diameter limit of a size A is about what you'd experience at - I think - about 62 diameters from the Size-1. A tiny planetoid exerts an influence out to 1000 kilometers, according to the venerable Traveller Handbook (presumably we're meaning a planetoid of 10 km diameter). A gas giant has a 100-diameter limit, even though the typical Sol system gas giant's density's about a quarter that of a terrestrial planet. Similarly, a star has a 100-diameter limit but, for sunlike stars, a density around a quarter that of the terrestrials.
So, the influence seems to be a spatial thing: a body's volume exerts a "shadow" into jump space, or perhaps into real space in some manner other than gravity, that influences the ability to transition to jump space (and that can prompt a precipitation out of jump space).
Can one presume ships likewise exert a "shadow"? If the little 10dT fighter's tenaciously matching course with you 50 meters to starboard, are you going to suffer the same penalty as if you were within 10 diameters of a world? Can you evade the pirate by jumping as he approaches to dock and board you, or are you risking a catastrophic misjump? Are there canonical descriptions of ships jumping with other ships close at hand, and do they discuss misjump?
A planet has a region in which it influences the transition to jump space, making it risky to jump when too close: the 100-diameter limit. How risky varies from game variant to game variant, but the 100-diameter bit's pretty consistent, as far as I know.
That influence does not seem to be related to gravity. A tiny Size-1 world has a 100-diameter limit, a big Size-A has a 100 diameter limit, even though gravity out at the 100 diameter limit of a size A is about what you'd experience at - I think - about 62 diameters from the Size-1. A tiny planetoid exerts an influence out to 1000 kilometers, according to the venerable Traveller Handbook (presumably we're meaning a planetoid of 10 km diameter). A gas giant has a 100-diameter limit, even though the typical Sol system gas giant's density's about a quarter that of a terrestrial planet. Similarly, a star has a 100-diameter limit but, for sunlike stars, a density around a quarter that of the terrestrials.
So, the influence seems to be a spatial thing: a body's volume exerts a "shadow" into jump space, or perhaps into real space in some manner other than gravity, that influences the ability to transition to jump space (and that can prompt a precipitation out of jump space).
Can one presume ships likewise exert a "shadow"? If the little 10dT fighter's tenaciously matching course with you 50 meters to starboard, are you going to suffer the same penalty as if you were within 10 diameters of a world? Can you evade the pirate by jumping as he approaches to dock and board you, or are you risking a catastrophic misjump? Are there canonical descriptions of ships jumping with other ships close at hand, and do they discuss misjump?