This archive tracks four layers. A record present in 2 of them (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
[RECORD LOST]
No record for this location in Age of the Imperium.
The 41st Millenniumpre-Rift
imperium
Fortress-convent, and the first Necron contact
A convent of self-denial on a barren world, and the place the Imperium met the Necrons for the first time and did not survive the meeting. The second visit is the novel.
Era Indomituspost-Rift
none
[RECORD LOST]
[RECORD LOST]
Nothing survives in the archive for Era Indomitus.
Position
Map frame: 905, 495 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 405 units ≈ 43.1k light years, east of the galactic core.
Height above the disk plane: 9.4 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
System: Sanctuary 101 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.
Every fact in this record, and where it came from. Editorial derivations say so.
regionhigh
wh40k.lexicanum.com/wiki/Sanctuary_101 'established on the barren and lifeless planet with the same name located in the Vidar Sector on the Eastern Fringes'; https://wh40k.lexicanum.com/wiki/Vidar_Sector — 'an Imperial Sector located in the Eastern Fringe … somewhere north of the Tau Empire'
gposlow
inferred: sector-level, and a good one — the Vidar Sector is published as Eastern Fringe and north of the T'au Empire, so the marker sits on the Ultima eastern rim above the T'au worlds. No system is published. Sprint 3 dropped the book because the CONVENT has no infobox; the sector statement in its own lead was the fact it needed