Astrum Aureus

Type	Boss
Environment	Astral Infection
Damage	0 (Contact); 145 / 220 / 242 / 264 / 429 (Jump); 88 / 156 / 184 / 212 / 318 (Astral Laser); 100 / 172 / 208 / 244 / 366 (Astral Crystal)
Max Life	100,000 / 160,000 / 192,000 / 204,000 / 244,800
Defense	40
DR	50%
KB Resist	100%
Inflicts debuff	Astral Infection 100% chance;
Debuff duration	0.75 second (Astral Laser); 1.25 seconds (Astral Crystal); 3.33 seconds (Contact)
Debuff tooltip	Your flesh is melting off
Immune to
Cold	-
Water	-
Sickness	Resistant
Electricity	-
Heat	Vulnerable
Coins	60

"With this experiment concluded, he will certainly be examining you next. Watch yourself."

Not to be confused with Astrum Deus, a similarly-themed worm-like boss.

Astrum Aureus is a Hardmode boss fought in the Astral Infection biome. Defeating it grants access to new Astral-themed gear from various sources.

Defeating Astrum Aureus is also a repeatable method to cause Astral Infection meteors to fall in the world, but only under the right conditions or if an Astral Infection meteor is not already present in the world.

Spawn

Astrum Aureus does not spawn on its own and must be summoned using the Astral Chunk in the Astral Infection biome.

Behavior

When first summoned, Astrum Aureus will be in its recharging phase, indicated by the lack of astral flames. While recharging, Astrum Aureus deals no contact damage and has halved defense and damage reduction. After several seconds, its flames will ignite and it will begin to attack the player, cycling through a specific attack pattern before re-entering its recharging phase and repeating the attack cycle. The time it spends in its recharging phase decreases as its health decreases. It will stay in its idle and walking phases for a shorter time if it gets hits or the player is too close to it. All of its attacks inflict the Astral Infection debuff.

If the player leaves the Astral Infection biome during the day, it will cause Astrum Aureus to enrage, drastically increasing its movement and jumping speed and completely removing its recharging phase. Astrum Aureus never enrages anywhere during the night.

Attacks

Crawls towards the player and fires spreads of lasers at them, alternating between normal and offset spreads. Astrum Aureus will fire 8 laser blasts before transitioning to its next attack.
- During this attack, Astrum Aureus can move through tiles.
- The number of lasers fired per blast increases as its health decreases.
Makes a far and tall jump towards the player. If the player moves under it, it slams down, changing its horizontal speed to try to land on them. When Astrum Aureus lands, it fires a laser spread at the player. Astrum Aureus performs this attack 3 times before returning to its recharging phase and repeating this attack cycle.
When at 75% health, Astrum Aureus will alternate between firing spreads of lasers or 2 Astral Flame Crystals with each jump. These flame crystals home in on the player after 2 seconds and after 3 more seconds pass or they get close to the player, they will lose their homing ability and gradually accelerate, eventually flying off screen.
When at 50% health, before returning to its recharging phase, Astrum Aureus will instead stand still and fire 2 consecutive Astral Flame Crystals upwards, then teleport close to the player.
- Astrum Aureus is in its recharging phase when it teleports, preventing it from hitting the player when it does so.
When at 50% health, it cycles through all attacks 50% faster.

In Expert Mode

Stays in its idle and walking phases for an even shorter time when getting hit or the player is too close to it.
Gains the ability to jump through tiles.
Gains movement and jump speed as its health decreases.
Time spent in its recharging phase is decreased.
When at 80% health, it will start firing sets of 4 astral flame crystals, which increases as its health decreases.
Summons 2 Aureus Spawns each time it teleports. Aureus Spawn chase players and attempt to explode on top of them, glowing and chasing faster if it is at 50% health. If an Aureus Spawn is at 50% health and collides with Astrum Aureus, it will explode to damage Astrum Aureus for a small percentage of its maximum health.

In Revengeance Mode

Movement speed is increased, increasing even more as its health decreases.
Gains jump height the further up the player is from it.
Time spent in its recharging phase decreases even further as its health decreases.
Fires many more astral flame crystals.
When at 80% health, it will start summoning Aureus Spawns.
When at 30% health, the number of stomps and lasers are increased, and its fall speed changes with each jump.

In Death Mode

Now damages itself for 1% of its health to summon Aureus Spawns, up to a minimum of 1 remaining health.
Increased velocity and spread of astral flame crystals.
Aureus Spawns charge at the player for 10 seconds instead of 5 before exploding.
Aureus Spawns can fire homing astral flame crystals every 3 seconds while not charging.
Aureus Spawns can now move away from other Aureus Spawns.

In Master Mode

Stays in its idle and walking phases for an even shorter time when getting hit or the player is too close to it.

On the For the worthy seed

Is 20% smaller.
Walks and falls 15% faster.
Astral Flame Crystals are twice as fast.

Summons

Image	Name	Condition
	Aureus Spawn	In Expert Mode or in the Boss Rush

Resistances

Astrum Aureus takes reduced damage from most non-minion piercing projectiles. Each hit decreases the damage of the next hit by 12%, until the eighth hit onwards which deal 20% of original damage.
Astrum Aureus also takes 70% damage from The Ballista's greatarrows.

Aftermath

Another Astral Meteor will spawn in the world (under the right conditions).
The Drunk Princess will begin selling Everclear, the Star Beam Rye at night, and the Bloody Mary during a Blood Moon.
The Astral Chest will be unlockable in the Dungeon.
Several Astral Infection enemies will become stronger and drop unique items:
- The Mantis will now drop the Astral Scythe.
- The Atlas will now drop the Titan Arm.
- The Nova will begin to drop the Stellar Cannon.
- The Aries will begin to drop the Stellar Knife.
- The Astralachnea will begin to drop the Astralachnea Staff.
- The Astral Slime will begin to drop the Abandoned Slime Staff.
- The Hive will begin to drop the Hive Pod.
- The Hadarian will begin to drop Hadarian Wings.
- The Stellar Culex will begin to drop the Starbuster Core.
Astral Crates will contain Aureus Cells, Astral Injections, Gravity Normalizer Potions, and several items dropped by Astral Infection enemies.

Notes

Be careful straying too far from it (such as flying to high altitudes), as Astrum Aureus will despawn if it cannot teleport to the player.

Tips

For more elaborate strategies on defeating Astrum Aureus, including weapon and arena recommendations, as well as a more in-depth breakdown of the fight, see Guide:Astrum Aureus strategies.

General

Moving in a semi-circle around Astrum Aureus while it fires lasers can help the player successfully avoid them.
The astral flame crystals gain increased velocity and homing capabilities the closer they are to the player, making it essential that the player keeps their distance from them until they launch away.
In Revengeance Mode, avoid damaging the Aureus Spawns. They are initially harmless and will only attempt to harm the player if they take enough damage.
Astrum Aureus can be fought at the start of Hardmode, although it is not recommended to fight until the player has decent post-Plantera gear as its fast speed, height, and attacks can be easily overwhelming if unprepared.
- Should the player have the skill and patience to defeat it, they can obtain many powerful items from the boss.

Trivia

The Bestiary entry for Astrum Aureus: "Once meant for returning equipment from and surveying sites of prior battles, this creation of Draedon's was overtaken by the Astral Infection. Unfortunately, its defeat has released what power it possessed, granting it instead to the star's other warriors."

Astrum Aureus's theme is Interstellar Stomper, which was composed by the artist DM DOKURO.
Astrum Aureus replaces a removed boss, the Astrageldon Slime, which was a boss that fought much like the King Slime but was twice as big and emitted lasers in bursts at the player.
- Prior to Interstellar Stomper's implementation, Astrum Aureus's theme was Cosmic Disgust, which was originally intended for the Astrageldon Slime. This is why the theme's introduction contains a motif from The Slime God's theme.
Astrum Aureus's name roughly translates to "golden star" in Latin, although its name is actually a reference to an infectious bacteria named Staphylococcus aureus.
Astrum Aureus can be summoned as soon as Hardmode begins, as its summoning item only requires Fallen Stars and Starblight Soot.
Astrum Aureus's design was inspired by Security Robot B.O.X. from Metroid Fusion, as both their appearance and movements are similar, and are also both cyborgs that have been infected by a space infection.
If the Boss Checklist Mod is installed, its unique despawn message will be "Aureus has neutralized all threats. Resume prior reconnaissance."

History

edit

These history sections are still a work-in-progress, and may not yet contain changes relevant to the current version of the Calamity Mod.

2.0.4.003: Now stays in the idle phase and walking phase for a shorter time if it is getting hit or the player is too close to it. Getting hit or stay too close makes it stay in these phases for an even shorter time in Expert and Master Mode.

2.0.4.002: Buffed laser damage in Master Mode from 264 to 318 , and flame crystal damage from 300 to 366 .

2.0.4.001:
- Added now sounds for firing lasers, firing flame crystals, teleporting, and death.
- Now properly scales health in Master Mode. This should result in lower health overall.
- No longer uses a global scaling contact damage formula based on boss velocity.
- No longer enrages based on time in the Don't dig up seed.
- Buffed contact damage from 100 / 220 / 242 / 253 / 330 to 145 / 220 / 242 / 264 / 429 .
- Changed laser damage from 88 / 156 / 184 / 200 / 270 to 88 / 156 / 184 / 212 / 264 , and buffed flame crystal damage in Death Mode from 228 to 244 .
- No longer deals contact damage while not jumping.
- Now takes 70% damage from The Ballista's greatarrows instead of 65%.

2.0.3.007: Fixed its bestiary entry using the wrong apostrophe.

2.0.3.005:
- Decreased Astral Infection duration on contact from 4 seconds to 3.33.
- Decreased Astral Infection duration from lasers from 1 second to 0.75, and from flame crystals from 1.5 seconds to 1.25.
- Now takes 65% damage from The Ballista's greatarrows.

2.0.3.003:
- Decreased Astral Infection duration on contact from 8 seconds to 4.
- Decreased Astral Infection duration from lasers from 2 seconds to 1, and from flame crystals from 3 seconds to 1.5.

2.0.3.002: Now has a global pierce resistance.

2.0.3.001: Buffed health from 98,000 / 156,800 / 188,160 / 235,200 / 282,240 to 100,000 / 160,000 / 192,000 / 240,000 / 288,000 .

2.0.2.002:
- Changed Boss Checklist Mod despawn message from "Astrum Aureus' program has been executed. Initiate recall." to "Aureus has neutralized all threats. Resume prior reconnaissance."
- Lasers now have an acceleration of 0.5% increased velocity per frame (34.89% increase per second).
- Homing flame crystals now have 50% higher acceleration multiplier and 25% higher maximum speed in Death Mode.
- Now properly displays vanilla debuff colors and Hunter Potion effects.

2.0.2.001:
- Now deals no contact damage, and has halved damage reduction and defense while idle.
- Now stays idle for longer in later phases and has reduced speed.
- Added new sound effects for its jumps.
- Changed Bestiary entry from "A multi-legged mechanical beast, its very existence speaks of the extent of control the astral virus has. Not even machinery can stand against it." to "A multi-legged mechanical beast, its very existence speaks of the extent of control the astral virus has over the non-sapient. Not even machinery can stand against it."

2.0.1.003: Decreased hit sound delay from 20 to 16.

2.0.1.002:
- Added aftermath sound for spawning the Astral Infection.
- Changed the hit sound.

2.0.1.001:
- Removed the stat buff that it received after defeating Moon Lord.
- Now always drops Suspicious Looking Jelly Bean.

2.0.0.001:
- Now spawns 6 homing flame crystals instead of 9 flame crystals when it stomps.
- No longer drops Hallowed Key.

1.5.1.003:
- Now drops 60 .
- Buffed health from 89,200 / 142,720 / 171,200 to 98,000 / 117,600 / 188,160 .
- Nerfed post-Moon Lord health from 243,750 / 390,000 / 468,000 to 196,000 / 313,600 / 376,320 .
- Can now be damaged while it is teleporting.
- Increased walking animation frames-per-second by 50%.

1.5.1.001:
- Buffed base health from 84,000 / 134,400 / 171,200 to 89,200 / 142,720 / 171,200 , and post-Moon Lord health from 230,000 / 368,000 / 468,000 to 243,750 / 390,000 / 468,000 .
- Buffed contact damage from 80 / 176 / 198 / 209 to 100 / 220 / 242 / 253 .
- Buffed Astral Laser damage from 74 / 128 / 148 / 160 to 88 / 156 / 184 / 200 .
- Buffed Astral Flame Crystal damage from 80 / 140 / 160 / 172 to 100 / 172 / 208 / 228 .
- Buffed damage reduction from 15% to 50%.
- No longer decreases defense to 0 while idle.
- No longer deals contact damage while teleporting.
- Increased Astral Flame Crystal frequency and Aureus Spawn is moved from third phase to an added fourth phase below 40% / 50% health.
- Added a fifth phase below 30% health which increases the number of stomps and lasers, and causes fall speed to alter with each jump.
- Now vulnerable to heat debuffs, but resistant to sickness debuffs.
- Death Mode changes:
  - Now damages itself for 1% of its health to summon Aureus Spawns, up to a minimum of 1 remaining health.
  - Increased velocity and spread of Astral Flame Crystals.
- Now drops Gravistar Sabaton regardless of world difficulty.
- Increased Hallowed Key drop rate from 20% to 33%, and it now drops directly from the boss.
- Fixed the hitbox.

1.5.0.001:
- Nerfed defense from 50 to 40.
- Nerfed post-Moon Lord health from 624,000 to 230,000 / 368,000 / 468,000 .
- Nerfed Boss Rush health from 7,400,000 / 11,840,000 to 740,000 / 1,184,000 .
- Post-Moon Lord buff is no longer exclusive to Revengeance Mode.
- Decreased post-Moon Lord damage multiplier from 3x to 2x.
- No longer immune to any debuffs except Confused, Pearl Aura, Astral Infection, and Poisoned.
- Now always jumps towards a player instead of away from them.
- Can now walk on platforms in its idle phase.
- Decreased recharge timer from 2.5 seconds to 2. While enraged, it will no longer recharge.
- Now fires 6 crystals instead of 10 while above 75% health.
  - Crystals are no longer fired at the same time, they are now fired consecutively.
- Now has a third phase that starts at 50% health, during this phase, it now cycles through all of its attacks 50% faster. Its recharge timer does not change.
- Now utilizes three oval-shaped hitboxes to make the fight fairer.
- Now drops 25 instead of 35 .
- Decreased Fallen Star drop amount from 25-40 / 30-50 to 18-24 / 20-30 .
- Fallen Star drops are now compacted into stacks of 2.

1.4.5.004:
- Nerfed health from 96,000 / 153,600 / 195,200 to 84,000 / 134,400 / 171,200 .
- Nerfed Post-Moon Lord health from 704,000 to 624,000 .
- Nerfed Boss Rush health from 8,400,000 / 13,440,000 / 13,440,000 to 7,400,000 / 11,840,000 / 11,840,000 .
- Now less aggressive in Death Mode, and reduced the spread and amount of its lasers.
- Now enrages during the day.
- Now makes laser fire noises when stomping.

1.4.5.003:
- Buffed contact damage from 80 / 136 / 170 / 195 to 80 / 176 / 198 / 209 .
- Now fires more lasers, moves quicker, and has decreased attack delay as its health decreases in Death Mode.

1.4.5.002: No longer immune to the Life Drain debuff.

1.4.5.001:
- Jumps now try to intercept and slam the player if they are moving.
- Jump height now increases based on how high up the player is.
- No longer immune to War Cleave.

1.4.4.002: No longer drops Lunar Fragments.

1.4.3.002: No longer immune to Celled, Dryad's Bane, or Oiled.

1.4.3.001:
- Nerfed contact damage from 80 / 136 / 170 / 195 to 80 / 136 / 156 / 168 .
- Nerfed pre-Moon Lord laser and crystal damage from 74 / 128 / 160 / 184 to 74 / 128 / 147 / 158 .
- Nerfed post-Moon Lord laser and crystal damage from 222 / 384 / 480 / 552 to 222 / 384 / 441 / 476 .
- No longer immune to Betsy's Curse.
- Death Mode changes:
  - Transitions into Phase 2 and 3 immediately instead of below 75% and 50% health.
  - Fires projectiles at the highest rate immediately, instead of gradually increasing rate as health lowers.
  - Runs, jumps, and falls at the highest speed immediately, instead of gradually speeding up as health lowers.
- Updated Boss Checklist's instruction to summon it.

1.4.2.108:
- No longer immune to Frostburn.
- Fixed a bug where defeating it would crash the game in multiplayer.

1.4.2.106:
- Buffed Boss Rush health from 1,400,000 / 2,240,000 / 2,560,000 to 8,400,000 / 13,440,000 / 1,440,000 .
- Nerfed contact damage from 90 / 144 to 80 / 128 , and defense from 70 to 50.

1.4.2.105:
- Can now jump further horizontally.
- Now falls more quickly while using its stomp attack and if the player is directly below it.
- Can now jump through tiles in Revengeance Mode.
- Lasers now pierce through the player.
- Flame crystals now fade in faster and have a significantly smaller explosion.
- Fixed recharging animation being drawn lower than intended.

1.4.2.104:
- Now inflicts Astral Infection for 4 seconds on contact instead of God Slayer Inferno for 3 seconds.
- Flame crystals now inflict Astral Infection for 3 seconds instead of God Slayer Inferno for 2 seconds.
- Lasers now inflict Astral Infection for 2 seconds instead of God Slayer Inferno for 1 second.

1.4.2.103:
- Buffed health from 80,000 / 128,000 / 163,200 / 252,800 to 96,000 / 153,600 / 195,200 / 299,200 , and nerfed defense from 120 to 70.
- Buffed post-Moon Lord health from 640,000 to 704,000 .
- Buffed Boss Rush health from 1,200,000 / 1,920,000 / 2,240,000 to 1,400,000 / 2,240,000 / 2,560,000 .
- Flame crystals are now easier to see.
- Flame crystals and lasers now have afterimages.

1.4.2.102:
- Now immune to Lava.
- Now drops Starlight Fuel Cell, Nebulash, and Hallowed Key.
- Decreased hit sound volume, and slightly increased hit sound delay.
- Now displays two status messages on defeat, indicating that the Astral Chest can be opened and that Astral Infection enemies are now buffed and have new drops.

1.4.2.101: Buffed health from 63,750 / 102,000 / 130,080 / 201,760 to 80,000 / 128,000 / 163,200 / 252,800 , and damage reduction from 10% to 15%.

1.4.2.002: Lasers now use sprites instead of drawcode.

1.4.2.001:
- Buffed health from 51,000 / 81,600 / 104,120 / 161,400 to 63,750 / 102,000 / 130,080 / 201,760 .
- Nerfed Boss Rush health from 2,400,000 / 3,840,000 / 4,480,000 to 1,200,000 / 1,920,000 / 2,240,000 .
- Decreased Post-Moon Lord minimum coin drop count from 3 to 35 .
- Lasers can no longer be shot while teleporting.
- Projectiles now have more descriptive names.

1.4.1.003:
- Decreased minimum coin drop amount from 20 to 15 .
- Increased the volume of hit sound, and increased the delay between when hit sound can play.

1.4.1.001:
- Buffed Boss Rush health from 1,000,000 / 1,600,000 / 1,840,000 to 2,400,000 / 3,840,000 / 4,480,000 .
- Buffed base contact damage from 70 / 112 to 90 / 144 .
- Increased God Slayer Inferno duration from contact from 2.5 seconds to 3.
- Increased God Slayer Inferno duration from crystals from 1 second to 2.
- Now has set amounts of contact damage per phase instead of having damage based on health.
- Now drops Greater Healing Potions.
- No longer takes 50% damage from Crystal Bullet shards, Holy Arrow stars, split Terra Arrows, and split Terra Bullets.

1.4.0.002:
- Decreased the size and amount of dust.
- Fixed it still appearing as Astrageldon Slime on the Boss Checklist mod's boss checklist.

1.4.0.001:
- Introduced as a replacement for Astrageldon Slime, with the following changes:
  - Nerfed health from 61,000 / 97,600 / 129,720 / 188,600 to 51,000 / 81,600 / 104,120 / 161,400 , buffed contact damage from 10 / 16 to 70 / 112 , and buffed defense from 0 to 120.
  - Now has 10% damage reduction.
  - No longer jumps at all times.
  - Now shoots blasts of lasers in succession instead of shooting a blast of fireballs after every few jumps.
  - Now shoots homing crystals in multiple directions instead of fireballs.
  - Now spawns Aureus Spawns occasionally in Revengeance Mode and higher.
  - Will now occasionally attempt to jump onto the player.
  - Will now occasionally teleport above the player.
  - Now uses a custom hit sound.
  - Now has a unique sound when landing on tiles.
  - No longer has transparency.
  - Resprited it and map icon. Previous sprites were

Navigation menu

Namespaces

Views

Navigation

Resources

Items

Characters

Portals

Tools

In other languages

Astrum Aureus

Contents

Spawn