From Lexicanum

Map	Basic Data		Planetary Image
	Name:	Cyrene
	Segmentum:	Unknown
	Sector:	Korianis Sector
	Subsector:	Unknown
	System:	Unknown
	Population:	None
	Affiliation:	Imperium
	Class:	Dead World
	Tithe Grade:	Unknown

The Planet

Cyrene was a verdant world where the Blood Ravens chapter had their Blood Trials. The world possessed a large proportion of mutants, and particularly psykers.

When it was discovered that Cyrene's population had become completely corrupted, the planet was destroyed through Exterminatus by lance strikers, mass drivers and Cyclonic Torpedoes ordered by the Inquisition and the Cyrenian Blood Raven Captain Gabriel Angelos.

Sources

• Blood Ravens Index Astartes entry - GW website