The Vela Pulsar was a Pulsar in the Beta Quadrant, part of the Vela constellation. The pulsar's output of deadly radiation partially propagated through Subspace, and the subspace in the region around the pulsar is highly unstable. Warp fields anywhere in the system can further destabilize the pulsar itself, leading to more deadly radiation.
The pulsar has one planet, Ta'ith, which is home to a sentient species known as the Ta'ithans. They are descended from an ancient advanced race known as the Whetu'irawaru. (TTN novel: Fallen Gods)