61 Cygni was a warm yellow star, with a habitable zone covering the third and fourth planets. All this changed during the mutiny, when CSA renegades began seeding the star with degenerate matter. This served two purposes: to destabilize the star, and to make it seem as if this was a natural occurrence, since degenerate matter generally appears within stars about to go or having recently gone nova. The culmination of this plan was when the CSA Legend Seeker, long believed to be at the heart of the most recent mutinous uprisings, launched a series of torpedoes at 61 Cygni. These torpedoes detonated, forming small collapsars that ripped through 61 Cygni. (Needless to say, these torpedoes are -not- standard Cygnus technology.) The destabilization was catastrophic and the star immediately began to detonate. If not for the fact that it was already known that the star would go nova -- albeit at a somewhat future date -- then evacuation plans would not have gone nearly as well. The CSA Blacksilver, carrying the populations of Tharkold and Cygnus Prime, fled through the 61 Cygni jumpgate, and soon arrived at Alpha Cygni. Both Cygnus Prime and Tharkold were devastated.
Currently, 61 Cygni is somewhat less massive than before, having shed most of its heliosphere in the nova. The Sciences Division believes the remains of 61 Cygni will eventually coalesce into a neutron star or white dwarf. The system is still filled with a dangerous amount of radiation as 61 Cygni continues to experience increased solar flare activity. Both of the inner planets were immolated, rendered into glazed balls of rock.
Cygnus Prime had been inhabited a long time ago, by a highly advanced civilization. The history and nature of these people remain a mystery, though they left behind a great many of their artifacts, including the famed Gunslinger-class destroyers and the Walker-class destroyer escorts. The CSA, in fact, managed to salvage a number of Gunslingers.
Thunderstruck City
This was the settlement belonging to the BIS, built around the crash site of the BIS Thunderstruck, built on the ruins of an Old Cygnian installation. The primary purpose of the city was to support salvage work on the Old Cygnian ruins. As time progressed, it became the cultural and political capitol of the Cygnus Solar Alliance and later, the Cygnus Sector Authority. The city was only lightly damaged during the first incidence of the mutiny. Later, Thunderstruck City suffered immense devastation at the hands of renegade Delphian forces, from burrowing gravshock devices. The final destruction took place when 61 Cygni went nova; a piece of the heliosphere impacted within one mile of Thunderstruck City, flattening it. Very little remains of the city.
GATEWAY IV -- THARKOLD
Tharkold seems to not have been native to the 61 Cygni system. This is based on geological and mineral evidence. Like Cygnus Prime, Tharkold appears to have housed an advanced civilization, though the one on Cygnus Prime was obviously capable of interstellar flight, while the one on Tharkold seems to have ended in the early atomic era. What is known is that some sort of war ended most higher forms of life on the planet many, many centuries before.
Aurioch
The ruins of the city of Aurioch were, for a time, the primary landing site for the CSA on Tharkold. While the city and surrounding countryside were ravaged, the airport or spaceport appeared to be in relatively decent condition, allowing use of these facilities. In addition, the spaceport was within twenty miles of one of the largest fertile locations on the planet. While spared much of the destruction that was visited upon Cygnus Prime, the wavefront of the nova made the environment of the planet inhospitable. While it was still in use, there was little to be found in Aurioch outside of archaeological interest.
Mons Beyelborg Agricultural Facility
Mons Beyelborg was the main provider of the CSA's food production. It was also, ironically, the location of the first penal agricultural unit. Enough foodstuffs were produced to yield a surplus that was sold to foreign interests. The usefulness of Tharkold as an agricultural world was ruined when 61 Cygni went nova. The intense radiation and particulates from the exploding heliosphere was devastating to Tharkold's ecology, and a scout expedition to Tharkold reported that the planet would not recover from the disaster anytime in the near future.