The Gate is a 10 light-year wide structure at the top of Vesania.
The gate appears as a swirling mass of glowing dust, and spectroscopy indicates proportions of elements which would be standard to an O-class star.
Ships attempting to go towards it experience a sudden wave of nausea then come to facing the other way. Automated structures experience the same.
It is known that The Gate is a relatively recent phenomenon, but just how recent is unknown.