The Bary (short for "barycenter") is a quintenary star system, meaning it contains five stellar components bound by their mutual gravitational attraction. Stars Alpha, Beta, Gamma, Delta, and Epsilon are all main sequence stars of spectral classes F5V, K2V, G3V, M1V, and M3V respectively. This hierarchical system can be simplified as four separate two-body problems. Stars Alpha and Beta orbit each other, as do Gamma and the closely bound Delta and Epsilon. Alpha-Beta and Gamma-Delta/Epsilon then orbit a common interstellar barycenter with a major axis of 0.247 LY.
Records are incomplete on the circumstances that led humanity to this place. Mentions of an old-world called Terra are numerous enough for social scientists to conclude that it must be the singular common birthplace of the human race. There is, however, no mention of where it might be located in the night sky. Given the disastrous tone of many ancient documents, that could be for the best.
It's known that the colonists came all at once, thousands of years ago. Hulking megaliths of incredible construction can be found dotted across the system. While mysterious and unthinkably large, these foundered colony ships do not appear to contain technologies much more complex than well-established science and engineering practices could make possible. Rather, the main question archeologists and engineers that study these wrecks have is how vessels many tens of kilometers in size could still be in decent condition after millennia of abandonment and decay.
Historians continue to piece together what fractured information they can to build a cohesive narrative. Are there other human civilizations out there, in other star systems? What became of the Terran Old World? Why make such a dangerous and lonely trek across space instead of addressing whatever was the impetus for humanity's exodus? The answers historians seek may one day be brought to light. For now, the descendants of Terra know that this is their lot.
In a sense, these Terran colonists lucked out. Interstellar space is unthinkably vast. Administering one city, nation, or planet is difficult enough. Managing an empire across the time lag of light-years is a futile endeavor. But multi-star systems such as The Bary have orbital spreads far less than a light-year. By settling a stable quintenary system with all five stars in relative proximity, five interstellar societies find themselves in regular diplomatic communication via high-gain radio.
Astronomical distance scales make diplomacy a benign affair. It takes several solid Terran years to traverse the world. Yet regular trade is booming.