This archive tracks four layers. A record present in 3 of them (AoI, M41, IND) is silent in the rest, and says so.
The Horus HeresyM30–M31
[RECORD LOST]
No record for this location in The Horus Heresy.
Age of the ImperiumM32–M40
imperium
Extermination target, then a grave
A xenos-infested world the Imperial Fists went to clear, which is why the Chapter was off Terra's walls for the first time in a thousand years when something far worse arrived. Almost the whole Chapter died here, and the War of the Beast started from it.
The 41st Millenniumpre-Rift
none
Dead world
[RECORD LOST]
Nothing survives in the archive for The 41st Millennium.
Era Indomituspost-Rift
none
[RECORD LOST]
[RECORD LOST]
Nothing survives in the archive for Era Indomitus.
Position
Map frame: 295, 585 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 222 units ≈ 23.6k light years, south-west of the galactic core.
Height above the disk plane: 2.0 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
System: Ardamantua System
Books set here
2 titles in the reading tracker touch this record, 1 of them as a primary location. Titles link out to the tracker.
wh40k.lexicanum.com/wiki/Ardamantua infobox Class = Dead World; Affiliation = Imperium; lead reads 'was a world of the Imperium' (past tense)
gposlow
derived: Segmentum Solar, no published sector or system. The Imperial Fists reached it as a routine compliance action from Terra, so it is placed inside the Solar block within easy reach of Terra, south-east of it. Relational and weak — no bearing is published