The giant stars orbiting the supermassive black hole at the centre of the Milky Way Galaxy
Supermassive black hole in the centre of the Milky Way. It is surrounding by concentric rings of rapidly expanding matter, evidence of a massive explosion.
The supermassive hole and its environs has been observed by the telescopes of the Terragen Civilisation for ten thousand years, and conclusive evidence indicates that Sgr A* is surrounded at some distance by an advanced civilisation assigned the label HEEC-MW-1.
Several long-distance missions have departed towards Sgr A*, but will not arrive for tens of thousands of years.