The Galen system - an overview

The adventure “Tyranny of the Daleks” is set in a binary star system, known as Galen.  The larger of the two stars is Galen Alpha, a main sequence G1V spectrum star. It is orbited by Galen Beta, a red dwarf star. The Galen system is at the absolute tail end (and possibly beyond that) of the Carina-Sagittarius arm of the Galaxy, in practical terms on the other side of the galaxy from the Sol System and about as far away from Sol as it is possible to be without leaving the galaxy, at around 75,000 light years distant.  It is approximately 30 light years below the galactic plane. 

The interstellar region around the Galen system is rather empty, and the nearest star is roughly 27 light years away.  This has resulted in the Galen system being entirely overlooked and untouched by any external influence until the arrival of the Federation long range scientific vessel, the F.S.S. Thomas Stafford in 3827, which spent six months mapping it in outline in a preliminary reconnaissance mission before returning to its base of operations at the F.S.B. Lovell Deep-Space Observatory in the Yedrax Cluster.

Galen Beta has a relatively large and surprisingly circular orbit. Ordinarily the orbit of Galen Beta should, according to mathematical modelling, be where the Oort Cloud for Galen Alpha would be but Galen Beta has effectively swept away the protoplanetary disc of material. This configuration has shaped the distribution of matter in the system, suppressing the formation of additional terrestrial planets close to the primary star and creating a distinctive pattern of cometary and minor body orbits.

The position of the Galen System in the Milky Way

The Galen Alpha planetary system consists of ten principal bodies, each of which has at least one natural satellite. Unusually it has three major supra-Jovian class planets. The rest are two Neptunians along with five terrestrials, two of which (those most immediate to Galen Alpha) are telluric or silicate bodies whilst the outermost three are typical plutinos. There are two insubstantial asteroid belts, one between Galen Alpha III (or Karvtal) and Galen Alpha IV (or Lanetarg) and the other between Galen Alpha V (Mercula) and Galen Alpha VI (Terskan). The system presents as having a comparatively high level of matter, particularly for one positioned so far from the galactic core.  Galen Alpha II, known as Galentor, is a fertile garden world, hosting a young and rich biosphere.

The Galen Beta planetary system is much less substantial, consisting only of two small sub-Neptunians, each with its own system of satellites. None are considered suitable for settlement without substantial terra-forming. Galen Beta itself is considered to be a failed main sequence star and without the consumption of Galen Alpha's protoplanetary material may well have concluded at the brown dwarf stage.

The region around the Galen System is extremely sparsely populated. Within a 50-light-year radius, there are only a handful of known stars. There are no large open clusters or prominent nebulae in the immediate vicinity, and the galactic background density of stars is significantly lower than nearer to the galactic core. This isolation has contributed to the relatively undisturbed development of Galen Alpha II, Galentor, with minimal external influences such as supernova shockwaves or heavy interstellar radiation flux.

Interstellar travel in this region is further complicated by the low frequency of navigational landmarks. The four nearest known systems are:

• Virellon System, 27 light-years from the Galen System, a pale blue-white F-type star illuminating a scattered belt of crystalline asteroids. Old Federation deep-space probes once detected strange harmonic radio emissions from within the Virellon Belt, never explained, and now long forgotten. Local legends speak of “the Singing Stones of Virellon.”

• Orrath System, approximately 32 light-years distant, a dim K-class subgiant surrounded by drifting remnants of a once-massive gas giant, destroyed in an unknown cataclysm. Its sole surviving world, Orrath IV, known as Olyrra, supports vast fungal plains that glow faintly in darkness, bioluminescent ecosystems linked by chemical communication across continents, which are reminiscent of organic forms found on Galentor.

• Thyraxis System, 34 light-years away, notable for its bright K-type main-sequence star and a wide circumstellar ring of debris thought to be the remnants of a failed planetary system.

• Yedrax Cluster, 41 light-years distant; a small, tightly bound group of four K- and M-class stars with a rich circumstellar medium. It hosts the F.S.B. Lovell Deep-Space Observatory, a Federal Empire station dedicated to exploration, scientific observation, and long-range surveys of outer galactic space and indeed intergalactic space. The Yedrax Cluster is becoming a key forward outpost for monitoring interstellar phenomena and emerging threats to Federal Empire space.

This small grouping of stars makes up the closest this part of the galaxy has to a cluster or a stellar association, and is known as the Tharyn Assemblage, after Professor Vek Tharyn, the Draconian astrophysicist who formed part of Doctor Xafonix’s team.  Professor Vek Tharyn discovered that this small grouping of stars is found within a localised region centred on the Thryaxis System, roughly spherical in shape and 50 light years in radius, which is denser than the surrounding very thin interstellar medium this far out from the galactic core.

Beyond this localised density of the interstellar medium, space in these far reaches of the galaxy is very thin and the interstellar medium here is much less dense than that around Earth’s Solar System.  The Galen system is some 5,000 light years from the effective edge of the stellar disk of the galaxy, that is the part of the galaxy containing the spiral arms and their stars.

The Galen System is effectively a cosmic island, where phenomena such as interstellar cloud encounters, nearby supernovae, or perturbations from stellar neighbours are rare, making it one of the quietest and most stable sectors for long-term planetary evolution. This isolation has aided the stability of Galentor’s biosphere, leading to an extraordinarily interdependent ecosystem.

Prior to the inauguration of the Galactic Federation, the whole region in which the Tharyn Assemblage is found was claimed by the Draconian Empire, although during this period it was never explored or even reached.  

In practical terms, Galen’s location at the very edge of the galaxy means that exploration and supply missions from the Galactic Federation or Federal Empire were always going to be infrequent and extremely delayed, giving any settlers a degree of autonomy uncommon in more densely populated regions of the Milky Way.

Galen Beta's orbit around Galen Alpha and its planetary system. The orbit of Falcoris around Galen Alpha is just about visible in this image.