Researchers found the first example of a rotating disk around a star outside the Milky Way. This structure is practically identical to those found around young stars in our galaxy, and may suggest that the formation of celestial bodies is similar at different points in the universe.
The star in question is located in the Large Magellanic Cloud, around 160 thousand light years from Earth. Its system, called HH 1177, is enveloped in a large cloud of gas.
The observation was made by the Atacama Large Millimeter Array (ALMA), a radio telescope opened in the Chilean desert in 2011, whose structure has more than 60 antennas. This project is the largest ever undertaken in terrestrial astronomy, capable of generating high-resolution images..
Artistic representation shows the HH 1177 system, located in the Large Magellanic Cloud.Source: ESO/M. Grain fairs
The discovery could impact the way scientists understand the formation of planets and stars, as it suggests 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 detected 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 Milky Way “Here, for the first time, we see direct evidence of this in another galaxy,” he added.
Accretion Discs
Since matter cannot fall directly onto a star, it is common for it to clump together and “plane” around the celestial body. Therefore, large disks of diffuse material are formed, which rotate faster as they approach the center. Known as accretion disks, they often form on young stars, black holes or neutron stars..
The gas in the center of the accretion disk (closest to the central object) moves faster than the matter on the periphery of the disk, and it is this variation in speed that draws attention to the presence 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 Moores University.
This is the same phenomenon that occurs when the pitch of an ambulance siren changes as it passes you, and the frequency of the sound goes from higher to lower. In traditional physics, we call it the Doppler effect. In astronomy, it is known as “redshift” or “blueshift”, depending on whether the observed object is moving closer to or further away from Earth.
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2023-11-30 19:00:00
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