The Sig System is one of the core systems of the Human Imperium in Acheron Roe, it is located in Hex #0306 . Compared to its neighbours and peers Sig is unusual in that it contains significantly fewer substellar objects than might otherwise be expected for a system of its type and age. Despite this it is perhaps the most culturally significant system of the Empire after Imperial Prime itself as it hosts Andophael; the Holy Planet and home-world of the High Church of the Messiah-Emperox, the imperial state religion. Millions of pilgrims from across the Empire make the journey to Andophael each year to walk the Path of Virtue and visit the Grand Temple; bringing with them tithes, donations and commerce that form a significant part of the High Church's economy.

The system's immediate drive-space neighbours are Alvero (0406) and Tsatsos (0407)

Star System

The Sig System is a 'failed binary' star system named after it's primary star, Sig-A and its substellar companion Sig-B Shiva.

Sig-A Sig

Sig-A is usually simply referred to as Sig, like the system itself. It is a type A blue-white main-sequence dwarf apoxmately 1.77 solar masses in size. Like other type-A stars Sig is very bright, emitting up to ten times the output of humanity's ancient native star. A much larger part of these emissions are also made up of Ultra-Violet radiation. Additionally the star blows a much strong stellar wind than Sol and it rotates fast enough to complete a full rotation every 31.4 standard days. This rotation produces a very potent stellar magnetic field.

Sig-B Shiva

Sig-A's companion and also the innermost object of the system is Sig-B Shiva, commonly referred to simply as Shiva. Shiva is a large M-Class brown dwarf of 0.061 solar masses. It is not large enough to become a star, but is much too large to be a planet. Hence why the system fails to classify as a ture binary. Shiva has a very low luminosity and almost all of its emissions are in the infra-red part of the EM spectrum. Those parts that are visible to the human eye make it appear a dark red-purple in colour. Shiva orbits Sig at a distance of 11 light-minutes and one orbital period lasts approximately 195 standard days.

The Emperox's Halo

Sig-B Shiva posseses an impressive ring system known as the Emperox's Halo for the unusual visual effect produced when the brown dwarf passes across Sig. On Andophael a day when such an eclipse will be observable from the surface is considered a holy day and almost all pilgrim travel packages and self-planned pilgrimages will coincide with one of these days. The Halo was formed from planetary debris in the earlier stages of the system's development.

After a number of accidental deaths from Pyxis Seekers attempting to perform a fusion-burn assisted slingshot maneuver around Sig and through the Halo, the Church placed a warning buoy in 3024. There has not been a corresponding decrease in attempts however, and each year a maintenance crew flies out to the buoy to remove Pyxis decals from the transmitter assembly.

Coppernicus Mining Project

There is a ruined pre-scream deuterium mining facility in orbit of shiva, however the technology and expertise required to operate it no longer exists in the Empire so it currently cannot be restored. The only interest in it is from salvagers and scrappers.

Occupation:Scrappers in the ruined old mine

Situation:Things are emerging below

Planetary System

Shiva's enormous relative mass was extremely disruptive to the formation of large astronomical bodies such as planets during the early formation and development of the Sig sytem. Its gravitational influence spelling doom for the other astronomical bodies by disrupting their orbits either directly or indirectly. Once destabilised these objects would fall towards Sig or Shiva. Direct impacts would likely have been quite rare; mostly these objects would either be torn apart by the tidal forces, scattering debris across the system, or be thrown outward by gravitional slingshot mechanics. Possibly out of the system entirely.


High Church Homeworld. The planet Andophael, the next object in the Sig system, is the lone survivor of Shiva's wrath having formed far enough away to escape the deadly gravitic influence. It orbits Sig at a distance of 44 light-minutes. Though of course as a consequence of being so far out it also experiences extremely cold temperatures despite the intense luminosity of Sig; with little surface water and precipitation.

Andophael was not entirely unaffected by Shiva however. The planet has suffered numerous impacts with asteroids and other debris that were thrown out of the inner system by Shiva. Due to the young age of the planet, it's mild tectonic activity and the relative lack of erosion factors, most of the impact craters remain visible to this day, particularly the largest ones such the Grand Chalice in which the Grand Temple was constructed and the Eye of Providence. The planet's moons were also all 'captured' by its gravity after they were thrown out of their orbits further in system. Fortuitously, or perhaps, miraculously, their combined tidal effects heat and drive the planet's otherwise inert core, without which the powerful magnetosphere that protects the surface from Sig's intense UV radiation and solar wind would not exist.

Andophael is slightly larger than ancient earth but is also less dense, giving it a surface graity of just below human native at 0.97 G.

Satira Pala

Satira Pala is a dwarf planet that orbits in the L2 Lagrange Point between Andophael and Sig meaning that is always 'behind' the planet. Due to Satira Pala's small size, at less than a thousand kilometers in diameter, and close proximity to Andophael, it is commonly classified as one of the planet's moons even if this is technically incorrect. It has an extremely weak surface gravity of 0.01 standard Gs and has no atmosphere at all. Satira Pala experiences a permanent night time with Andophael always eclipsing Sig, this does however effectively shield it from the solar wind and stellar radiation. For this reason Satira Pala is home to a number of communications stations, listening posts, radio telescopes and other scientific facilites, as well as training facilities for the Inquisition, the High Church's internal police force.

The Necropolis

The Necropolis is a large belt of asteroids and planetoids that orbits Sig beyond the orbit of Andophael. While some of the material in the belt is simply standard left overs from the formation of the system much of it is made up of inner system debris that settled into a new orbit and some is even the remnants of potential proto-planets that did not survive encounters with large objects thrown from the inner system. For these reason it earned it sombre name.

There are three objects in the Necropolis are large enough to be classified as dwarf planets, upon which a vast network of underground tombs have been constructed. These are managed by a group of Neshmet, to perform rites, and a group of clergy to maintain and clean the catacombs. In these tombs are lost Relics, entombed bodies of Clergymen and documents believed to be lost, that may point to evidence of things as yet unknown about the sector.

Occasionally perturbations between the various objects in the Necropolis will throw one of back out into the wider system. These asteroids are affectionately termed Phantoms.


Sheol is the second planet and final part of Sig's planetary system. It is an extra-solar capture much older than the Sig system itself, one of the reasons that the Fitzroy 7 research base is located there. Sheol seems otherwise unremarkable. It is a small world made of rock and ice that has a very thin atmosphere of nitrogen and hydrocarbons, brought about by exposure to cosmic radiation. It has a mass of about 0.04% that of Andophael and surface gravity of 0.15 standard G. In 3211 the planet will have completed it's first ever full rotation around Sig since it was first observed by humanity.

Fitzroy 7

Occupation: Experiments that have gotten loose

Situation: Selling black-market tech