Signus Alpha

Signus Alpha is the red-giant primary star of the Signus Cluster, the location of the Blood Angels’ trap during the Horus Heresy. It is distinct from Signus Prime, the daemon capital of the cluster, and is recorded on this map as a star within the signus-system entry.

The novel Fear to Tread describes the cluster as lit by three suns and surrounding seven industrial worlds, to which Horus sent Sanguinius with the intention that he perish there. Signus Alpha is the ordinary red giant that the Blood Angels’ fleet first observed on arrival. The daemons Kyriss and Ka’Bandha devastated the planets of the cluster, but the star itself was unaffected. Sanguinius withdrew the Legion from the cluster and declared the whole region forever dead.

Signus Alpha remains significant as the principal sun of the cluster rather than as an inhabited hive world. This site retains it under signus-system as a star, does not attribute to it the Cathedral of the Mark, which belongs to Signus Prime, and does not reclassify the location as a planet.