The Ki Nebula is an ancient cloud of celestial gasses that occasionally coalesce into stars and even whole solar systems.
This nebula has the distinction of being the only celestial feature that inhibits access to Drift travel. All travel through the nebula must use standard thrusters.
Travel to the STX solar system is 2d6 days in a small or medium ship at maximum conventional thrust.
Travel to the AM solar system is 6d6 days in a small or medium ship at maximum conventional thrust.
Larger ships move slower and thus require even more time to move through the nebula. Smaller ships typically don't carry the required supplies to complete reasonable transit through the nebula.