The Astral Beacon is a Hardmode furniture item that can be crafted or found naturally on a pillar of Astral Monolith after the Astral Infection has generated. When right-clicked during the night, it is used to summon Astrum Deus while a Titan Heart or Starcore is in the player's inventory. Upon successfully summoning the boss, one Titan Heart is removed from the player's inventory if the player does not have a Starcore, and two stars rise up from the beacon, summoning Astrum Deus shortly after. If used during the day, the player is given a status message "The god of the stars rejects your offering. The ritual can only be performed at night."
- Astral Beacons cannot be destroyed by explosives. However, the Astral Beacons will be destroyed if any of the tiles supporting them can be exploded.
- Astral Beacons can be highlighted by the Spelunker Potion effect.
- If a meteorite hits the Astral Beacon, it may be destroyed and the player will have to craft another.