Ten billion years ago, another galaxy slammed into the Milky Way.
But it has so far taken astronomers to discover the massive, “fossil galaxy” that is still in our midst, according to a report in the Independent.
Researchers at the Apache Point Observatory Galactic Evolution Experiment (APOGEE) announced the discovery Friday, the Independent reports.
They have called the fossil galaxy “Hercules”, and they say that its stars were discovered within the “halo” of the Milky Way, the star cloud furthest away from the brighter center of our galaxy.
“It’s really small in the cosmological context – only 100 million stars,”
“But it accounts for almost half of the entire Milky Way’s halo,” added Schiavon, a scientist at Liverpool’s John Moore’s University’s Astrophysics Research Institute.
Dr. Schiavon and his team were able to separate the stars in the Milky Way and Hercules due to their different chemical composition and speed.
“APOGEE lets us penetrate that dust and look deeper into the heart of the Milky Way than ever before,” said Dr. Schiavon.
Based on the scientific data, the scientists have concluded that the collision between the two galaxies “must have been an important event in our galaxy’s history,” Schiavon said.
The researchers also stated that this incident makes the Milky Way unusual because other “spiral galaxies had much calmer early lives.”
As our cosmic home, the Milky Way is already special to us, but this ancient galaxy buried inside makes it even more special, ”said Dr. Schiavon.