Space & Astronomy

'Strange objects' spotted at the galactic core

By T.K. Randall
January 16, 2020 ·  7 comments

An artist's impression of what 'G objects' might be like. Image Credit: Jack Ciurlo / UCLA Found orbiting Sagittarius A* - the supermassive black hole situated at the center of the Milky Way galaxy - these perplexing astronomical peculiarities have been dubbed 'G objects'.

At a glance they appear to be giant gas clouds 100 times the size of the Earth's orbit around the Sun, but as they get nearer to the black hole they become strangely elongated.

"These objects look like gas but behave like stars," said physicist and astronomer Andrea Ghez.

The first two G objects (G2 and G2) were discovered two decades ago and now a team of astronomers from the University of California, Los Angeles has managed to find four more.

Even weirder still is the fact that these new additions (G3, G4, G5 and G6) have wildly different orbits.

"At the time of closest approach, G2 had a really strange signature," said Ghez. "We had seen it before, but it didn't look too peculiar until it got close to the black hole and became elongated, and much of its gas was torn apart."

"It went from being a pretty innocuous object when it was far from the black hole to one that was really stretched out and distorted at its closest approach and lost its outer shell, and now it's getting more compact again."

So what exactly are these G objects ?

Astonomers believe that each object may in fact be a pair of binary stars that have merged together into a single large star surrounded by a vast cloud of dust and gas.

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

Source: Science Alert | Comments (7)

Tags: Galaxy, Black Hole