Astronomers Get The First Glimpse Of Star Factory In The Center Of Milky Way

Astronomers have, for the first time, reconstructed the star formation history that occurred at the center of our Milky Way -- the star factory -- and found the star birth spread outward from the galaxy's center.

The study also discovered, contradictory to previous beliefs, the young stars in the densely packed galactic heart had loose associations, and that they drifted apart even further over millions of years.

To realize their experiment, the astronomers used the HAWK-I infrared camera of the Very Large Telescope (VLT) located in Chile, and conducted the GALACTICNUCLEUS survey wherein an area of 64,000 square light-years around the galactic center was studied in great detail, according to Space.com

Previously, only a few of these stars have been observed. This was despite the presence of a dense population of stars at the heart of the Milky Way, located roughly 26,000 light-years from Earth.

"Our study represents a big step forward in finding the young stars in the galactic center," research team member Francisco Nogueras-Lara said in a news release.

"The young stars we found have a total mass of more than 400,000 solar masses. That is nearly ten times higher than the combined mass of the two massive star clusters that were previously known in the central region."

The results of the study are crucial in understanding the rapid star formation that took place in the early history of the universe, and the starburst galaxies.

Starburst galaxies produce hundreds of solar masses per year in rapid star formation. This event occurs sporadically, lasting a few million years, which is relatively not a very long period on a cosmic scale.

While the Milky Way has low star-formation output, it still is useful for astrophysicists due to the central region of the galaxy. Its position allows for the investigation of star birth in other galaxies.

Interestingly, the core of our galaxy shows the characteristic rapid star formation of starburst galaxies and as such acts as a good proxy.

By studying the distribution of stellar luminosity for the stars, and categorizing them into a "brightness bracket," the astronomers could navigate their lifetimes, the number of stars formed at different times, and thus trace the process of star formation.

In one particular region of our galaxy, Sagittarius B1, it was observed the stars there were not part of a massive cluster, but were more dispersed. This was a testament to the fact that stars were formed in loose associations, which dissolved over the course of millions of years as they revolved around the center of the Milky Way.

The research team also discovered Sagittarius B1 and the innermost regions of the galactic center were riddled with older stars -- above the age of 7 billion years. This might indicate star formation started at the center of the Milky Way, and then moved outwards.

Nogueras-Lara and the team now aim to build on these observations with a different VLT instrument, called the K-band Multi-Object Spectrograph (KMOS) which is a high-precision spectrograph.

The results have been published in Nature Astronomy.