Astronomers spot young star forming like a planet

Dec. 14 (UPI) -- Scientists have spotted a young star forming in the disk of gas and dust surrounding another star. The young star is forming like a planet.

While studying the young massive star MM 1a, astronomers noticed an anomaly inside the star's rotating disc of gas and dust. Scientists think the observation is one of the first documented "fragmented" circumstellar disks.

Astronomers described the discovery this week in the Astrophysical Journal Letters.

"Stars form withing large clouds of gas and dust in interstellar space," John Ilee, astronomer at the University of Leeds, said in a news release. "When these clouds collapse under gravity, they begin to rotate faster, forming a disc around them. In low mass stars like our sun, it is in these discs that planets can form."

Instead of planets, scientists found another star.

Binary star systems are fairly common, but most feature stars born at the same time and with similar masses.

"Finding a young binary system with a mass ratio of 80 to one is very unusual, and suggests an entirely different formation process for both objects," Ilee said.

Among the cold outer rim of a circumstellar disk, gravity is unstable, and clumps of gas and dust form more easily. These conditions typically produce massive gas planets. In this instance, the unstable conditions inside the outer disk enabled the formation of another star.

Researchers used the ALMA array, a massive network of telescopes in the Chilean desert, to study the star system in fine detail. Scientists are planning to study the star system again, this time utilizing an even more powerful combination of ALMA telescopes.

The follow up survey could reveal another circumstellar disk sourcing the newborn star. Inside a second disk, scientists might find what they normally find in fragmented disks -- planets.