Great Spiral

The Great Spiral is the galaxy which contains the various nations and peoples of the Star Chronicle setting. It is a common name by which the galactic community refers to the entirety of the galaxy.

Prior to joining the galactic community, the Humans (now Antarans) referred to the galaxy as the Milky Way.

Structure
The Great Spiral is a barred spiral galaxy approximately 120,000 light years in diameter and containing nearly 400 billion stars. The various stars and gases at extensive ranges from the Galactic Center rotate at an average speed of 220 kilometers per second. A full revolution of the galactic mass is estimated to take approximately 240 million years. The entirety of the galaxy moves at an average speed of 600 kilometers per second with respect to extragalactic frames of reference. The Great Spiral is part of the Local Group, a subcomponent of the Virgo Supercluster.

Galactic Center
Refers to the rotational center of the Great Spiral. The sole point of note here is the supermassive quantum singularity known as the Well of Infinity, which is an extremely intense astronomical radio source. Able to be detected by modern sensors from any point in the Great Spiral, it is used as the general point of reference by navigation computers.

Galactic Deep Core
An extremely dense region of stars surrounding the Galactic Center, the Deep Core is home to some of the oldest stars in the Great Spiral and is a near-constant hotbed of activity. There are very few inhabitable worlds in this part of the Great Spiral, which the proximity of so many stars maintaining a state of near-constant daytime conditions.

Major exploratory efforts in this region only started about a century ago, and almost exclusively by military vessels. Because of the closeness of many of the stars in this region, accurate navigational charts of the few known safe routes are highly prized and are largely kept by government and military agencies for emergencies.

Galactic Core
Surrounding the Center and Deep Core regions, the Galactic Core is a heavily star-populated region. The southeastern fifth of the Core of the Great Spiral is home to some of the most important and prominent star systems in the galactic community. Herein one may find the capital worlds of the Antaran Empire, the Galarian TBD, the Namarian TBD, the So Andso.

Galactic Mid Region
The bulk of the galactic disc falls within what is called the Mid Region. Here one finds the majority of the populated worlds of Known Space, and a large portion of the exploration efforts currently underway into the other quadrants. Two particularly prominent areas of populated worlds in this area are the Tengel Cluster and the Ribom Expanse.

Galactic Rim
The peripheral edge of the galactic disc and the wilds of the galactic arms fall into the Rim region. Here one finds scattered independent colonies, distant worlds and some of the most lawless swaths of territory in the entire Great Spiral. The sole prominent world in this region is Old Earth, the dead origin world for the Antaran race.