Gaia data that helped produce the most accurate 3-d Map of the galaxy every has revealed a gigantic river of 4,000 stars that remained unnoticed.
And although it may be in plain sight, the cosmic river was only now spotted.
What makes it so exciting you ask? Well, according to astronomers, its proximity to Earth.
According to experts, it is located 100 parsecs away, which offers us an unprecedented opportunity to peer into the evolution of a star cluster that has been ripped apart by cosmic tidal forces.
The stream is relatively nearby and contains at least 4000 stars that have been moving together in space since they formed, about 1 billion years ago.
Due to its proximity to Earth, this stream is a perfect workbench on which to test the disruption of clusters, measure the gravitational field of the Milky Way, and learn about coeval extrasolar planet populations with upcoming planet-finding missions.
The discovery comes as an exciting one.
And it would not be possible if it were not for Gaia measurements.
The data gathered by Gaia made it possible for astronomers to measure the three-dimensional motion of stars in space.
By carefully observing the distribution of nearby stars as they moved together, one particular group of stars, yet unknown and unstudied, immediately caught the eye of the researchers.
It was a group of stars that showed precisely the expected characteristics of a cluster of stars born together but being pulled apart by the gravitational field of the Milky Way, note experts in a press release detailing the discovery.
“Identifying nearby disc streams is like looking for the proverbial needle in a haystack. Astronomers have been looking at, and through, this new stream for a long time, as it covers most of the night sky, but only now realize it is there, and it is huge and shockingly close to the Sun,” explained astrophysicist João Alves of the University of Vienna.
“Finding things close to home is very useful, it means they are not too faint nor too blurred for further detailed exploration, as astronomers dream.”
The newly found river of stars may help experts in measuring the mass of the galaxy.
“With follow-up work, this stream can tell us how galaxies get their stars, test the gravitational field of the Milky Way, and, because of its proximity, become a wonderful target for planet-finding missions,” the researchers explained.