“Exploring the Cosmic Dance: D9 Binary Stars in the Shadow of Sagittarius A*”

At the heart of our Galaxy lies an enormous black hole, and astronomers have detected a duo of stars moving in close proximity.

This black hole is referred to as Sagittarius A*, situated right at the center of the Milky Way.

Experts are aware that supermassive black holes exist at the centers of numerous large galaxies, and ours is certainly no exception.

In fact, these supermassive black holes are thought to play a crucial role in the development and evolution of galaxies.

Unveiling the binary stars

While binary stars are prevalent throughout the Universe, none had previously been identified in the vicinity of a supermassive black hole.

This find marks the inaugural discovery of a binary star system positioned near a supermassive black hole, occurring right at the core of our Galaxy.

Astronomers utilized information gathered by the European Southern Observatory’s Very Large Telescope to reach this conclusion.

They assert it assists in constructing an understanding of how stars endure in conditions of extreme gravity.

Moreover, it may ultimately facilitate the identification of planets near Sagittarius A*.

Insights gained

“Black holes are not as destructive as we previously assumed,” states Florian Peißker, a researcher at the University of Cologne in Germany and the lead author of the study published in Nature Communications.

It appears that some binary star systems can flourish even in such extreme environments.

The newly identified pair is named D9 and is estimated to be 2.7 million years old, categorizing them as young stars.

However, their existence is likely to be short-lived.

The gravitational pull of the supermassive black hole will likely lead the stars to collide and merge into a single entity within merely 1 million years, according to the astronomers.

In cosmic terms, these durations are virtually instantaneous.

“This provides just a fleeting opportunity on cosmic scales to observe such a binary system — and we succeeded!” exclaims co-author Emma Bordier, also a researcher at the University of Cologne and a former ESO student.

So, can stars genuinely form in the vicinity of supermassive black holes? It appears so. Several young stars have already been discovered near Sagittarius A*.

“The D9 system exhibits clear indications of gas and dust surrounding the stars, suggesting it could represent a very young stellar system that was formed near the supermassive black hole,” says co-author Michal Zajaček, a researcher affiliated with Masaryk University in Czechia and the University of Cologne.

The method of discovering the binary stars

The binary stars near Sagittarius A* exist within a dense stellar cluster orbiting the black hole, referred to as the S cluster.

Among these stars are ‘G objects’, which resemble stars in behavior yet look akin to clouds of gas and dust.

The astronomers were focusing on these peculiar entities when they noticed an unusual pattern in D9.

Data collected by the VLT’s ERIS instrument, coupled with historical data from the SINFONI instrument, indicated periodic changes in the star’s velocity.

“I initially thought my analysis was incorrect,” Peißker admits, “but the spectroscopic pattern spanned around 15 years, and it became evident this detection is indeed the first binary identified in the S cluster.”

Could the enigmatic G objects then potentially be a mix of binary stars that have yet to merge, along with debris from stars that have already fused?

Many inquiries persist, but the astronomers suggest that an anticipated GRAVITY+ enhancement to the VLT Interferometer and the METIS instrument on ESO’s Extremely Large Telescope could provide assistance.

These advancements will allow the team to scrutinize the center of our galaxy more closely.

“Our discovery enables us to speculate about the existence of planets, as these are often formed around young stars,” Peißker adds.

“It seems reasonable to think that finding planets in the Galactic center is merely a matter of time.”

The research findings were outlined in the paper A binary system in the S cluster close to the supermassive black hole Sagittarius A* (PDF) published in Nature Communications (doi: 10.1038/s41467-024-54748-3).