Sector 0257-0461: A few hundred minor warp-activities can be measured. Signatures are unknown and cannot be assigned to any known faction.
T+1 After Warp. Multiple groups of ships can be observed to scan nearby sectors.
T+3 After Warp. Asteroids appear to be harvested and ressources to be collected.
T+23 After Warp. Some sort of outpost seems to have been created in Sector 0257-0461. Signals seem to be able to be received. An automated message can be heard playing. "We are the Eridani. We have claimed this sector and see any attempt to enter Sector 0257-0461 as an act of hostility."
T+25 After Warp. A round superstructure, measuring a few kilometres in diameter has been built. Collectors are still harvesting materials in surrounding sectors.
T+26 After Warp. GSR ships have entered the sector without permission. Military forces are engaging. Construction will be continued.
T+27 After Warp. GSR ships have retreated. Construction is finished in T-3.
T+30 After Warp. Warpgate construction has come to an end. The four horsemen and the rest of the fleet has arrived in the sector.
T+32 After Warp. Ships of another faction scan from the very edge of the sector. They've been asked to identify themselves and to ceize the scanning.
The Eridani
The Eridani are home in a solar system stuck between dimensions. The warpgate presents the only known option to enter it.
Nobody really knows who they are, or what their motivations are. Their recent behaviour has been hostile and mistrusting towards any faction who has tried to establish contact.
From what we believe, the Eridani's home system "Epsilon Eridani" has been harvested scarce, their policies have drained available ressources and their population is starving. The only hope to survive the barren desert that Eridani Prime has become, is to venture outwards, to question their beliefs and to break their isolation.
The fleet of the Eridani shows a clear pattern that their ships follow. While heavily armed and armored, their propulsion technology is ancient by most standards, FTL is a completly new concept to the Eridani.
Diplomatics:
GSR - Hostile
Known Ships:

Classification: Light Battleship
Codename: War
Mass: 12301.9 Metric Tonnes
Crew: 816 Marines
Estimated Cost: 9.000.000 Credits

Classification: Heavy Battlecruiser
Codename: Conquest
Mass: 15714.9 Metric Tonnes
Crew: 876 Marines
Estimated Cost: 11.200.000 Credits

Classification: Dreadnought
Codename: Pestilence
Mass: 18080.3 Metric Tonnes
Crew: 846 Marines
Estimated Cost: 12.500.000 Credits

Classification: Heavy Battleship
Codename: Death
Mass: 17679.7 Metric Tonnes
Crew: 1030 Marines
Estimated Cost: 12.000.000 Credits

Classification: Strategic Fighter
Codename: Thunderbolt
Mass: 177.5 Metric Tonnes
Crew: 24 Marines
Estimated Cost: 130.000 Credits

Classification: Heavy Fighter
Codename: Warhawk
Mass: 294.4 Metric Tonnes
Crew: 34 Marines
Estimated Cost: 350.000 Credits