Scientists have discovered the first disk around an extragalactic star

Researchers found The first example of a rotating disk around a star outside the Milky Way. This structure is practically identical to that found around young stars in our galaxy, and may indicate that the composition of celestial bodies is similar at different points in the universe.

The star in question is located in the Large Magellanic Cloud, about 160,000 light-years from Earth. Its system, called HH 1177, is surrounded by a large cloud of gas.

This observation was made by the Atacama Large Millimeter Array (ALMA), a radio telescope that opened in the Chilean desert in 2011, and whose structure contains more than 60 antennas. This project is the largest ever in ground-based astronomy, and is capable of generating high-resolution images..

An artistic representation shows the HH 1177 system located in the Large Magellanic Cloud.source: ISO/M. Kornmesser

This discovery could impact the way scientists understand the formation of planets and stars, because it points to similarities between distant galaxies. This is what the project’s lead researcher, Anna McLeod, from Durham University, says.

“When I first saw evidence of a rotating structure in the ALMA data, I couldn’t believe we had discovered the first extragalactic accretion disk. It was a special moment. We know that disks are vital to the formation of stars and planets in the galaxy,” he added. “Here, for the first time, “We see direct evidence of this in another galaxy.”

Accumulation tablets

Since matter cannot fall directly on a star, it is common for it to collect together and move around the celestial body. Therefore, large discs of dispersed material are formed, which rotate faster as they approach the center. These disks are known as accretion disks, and they often form on young stars, black holes or neutron stars..

The gas at the center of the accretion disk (closest to the central body) is moving faster than the material on the periphery of the disk, It is this difference in speed that draws attention to the existence of this phenomenon.

“The frequency of light changes depending on how quickly the gas emitting the light approaches or moves away from us,” said Jonathan Henshaw, a researcher at Liverpool John Morris University.

This is the same phenomenon that occurs when an ambulance siren changes pitch as it passes you, and the sound frequency goes from higher to lower. In classical physics, we call it the Doppler effect. In astronomy it is known as “redshift” or “blueshift”, depending on whether the observed object is moving near or far from the Earth.

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