Strange objects spotted near black hole at the centre of our galaxy, scientists announce

Andrew Griffin
Artist's impression of G objects, with the reddish centers, orbiting the supermassive black hole at the center of our galaxy. The black hole is represented as a dark sphere inside a white ring (above the middle of the rendering): Jack Ciurlo

Strange objects have been spotted near the huge black hole at the centre of our galaxy.

Astronomers say they "look like gas and behave like stars" and represent a new class of unusual objects.

Four of the "G objects" have been found, orbiting around the supermassive black hole known as Sagittarius A*.

That mysterious swirling void is at the heart of our galaxy and continues to prove mysterious to the scientists who study it.

The four new objects join G1 and G2, which were found in 2005 and 2014 respectively, intriguing scientists because they seem to be compact most of the time but stretch out as they get closer to the black hole during their orbit.

These orbits are also a lot longer than the 365 days Earth takes to move around our sun, ranging from about 100 to 1,000 years.

Researchers at the University of California, Los Angeles, have fittingly named the newcomers G3, G4, G5 and G6.

Writing in the Nature journal, the group explained its belief that all six were once binary stars - a pair of stars which orbit each other - later merging as one due to the supermassive black hole's powerful gravitational force.

However, this merging process is not done overnight - it takes more than one million years to complete, said co-author Andrea Ghez.

"Mergers of stars may be happening in the universe more often than we thought, and likely are quite common," she explained.

"Black holes may be driving binary stars to merge. It's possible that many of the stars we've been watching and not understanding may be the end product of mergers that are calm now.

"We are learning how galaxies and black holes evolve. The way binary stars interact with each other and with the black hole is very different from how single stars interact with other single stars and with the black hole."

The team is already looking into other potential objects that may be part of the same family.

It says the research will help shine a light on what is happening in the majority of galaxies in our universe - though Earth is quite a distance from the action, "in the suburbs compared to the centre of the galaxy", Ms Ghez added.

Additional reporting by agencies

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