The Eos was a battlecruiser in service to the Dominion Fleet. After the Battle of Char, its crew sided with Valerian Mengsk in the conflict that broke out between his forces and those loyal to Arcturus Mengsk.
In the opening salvos above Char, the Antigone was able to take out one of Arcturus's battlecruisers via combined fire from the Antigone. As the battle progressed, the ship took damage, but responded to Valerian's order to meet at designated point of clear space within the Char system for a jump to warp space. The Dominion Fleet entered pursuit and kept firing. The Eos, already damaged, was hit and crippled.
Eos was the goddess of the dawn in Greek mythology.