Ten billion years ago, another galaxy slammed into the Milky Way.
But it has taken until now for astronomers to discover the massive, “fossil galaxy” still in our midst, according to a report in the Independent.
Researchers at the Apache Point Observatory Galactic Evolution Experiment project (APOGEE) announced the discovery on Friday, the Independent reports.
They’ve dubbed the fossil galaxy “Hercules,” and they say that its stars were discovered within the Milky Way’s “Halo,” the cloud of stars furthest from our galaxy’s brighter center.
“It is really small in the cosmological context – only 100 million stars,” Dr. Ricardo Schiavon said of the remnants of Hercules.
“But it accounts for almost half the mass of the entire Milky Way halo,” added Schiavon, a scientist with the Liverpool John Moores University’s Astrophysics Research Institute.
Dr.Schiavon and his team could tell the stars of the Milky Way and Hercules apart due to their different chemical composition and velocity.
“APOGEE lets us