Lambda radiation was a type of radiation inimical to all known lifeforms. One source of it was a particular class of stars. (Chronicle)
The first Federation encounter with lambda radiation was in the mid-23rd century, while the USS Farragut -- then commanded by Captain Garrovick -- was observing a non-allied Class M planet.
In 2370, the star of a Perseus Arm Class M planet flared with lambda radiation. The entire system was rendered uninhabitable.
40 years later, as the USS Witch of Endor approached the last known position of the missing USS Skyview, the sensors picked up asteroids with traces of lambda radiation. (Chronicle: "The Franklin Expedition")