Astronomers find remnants of the first stars in gas clouds

Scientists have discovered several remote gas clouds that have an increased magnesium content, but do not contain iron. This is what the remnants of the first stars should look like after they erupt as supernovae. Quasars helped to see all this. 

The chemical elements that left the first stars. Source: ESO/L. Calzada, M. Kornmesser

How the first stars in the Universe died

Astronomers working with the Very Large Telescope (VLT) of the European Southern Observatory have announced that they have managed to find the remains of the first stars in the Universe. They were found in very distant gas clouds, the chemical composition of which was determined using spectroscopy. 

The first stars in the Universe were born about 13.5 billion. years ago. Unlike modern ones, they consisted exclusively of hydrogen and helium and did not contain elements heavier than them in their composition. They exploded quite quickly as supernovae. Therefore, it is simply impossible to see the luminaries of the first generation now.

But they had to leave their characteristic mark in the Universe. The fact is that during supernova explosions, numerous heavy elements, up to iron, are formed, which then end up in gas clouds, from which the next generation of stars is formed.

However, in the early Universe, relatively low-mass stars could turn into supernovae. And the force of their explosions was not enough to form heavy elements such as iron, but it should have been enough to form carbon and oxygen.

How the clouds were found

Scientists could only look for gas clouds that would have a corresponding, very strange composition from the point of view of modern stellar evolution. And they found them in intergalactic space. We saw them as they were when the age of the Universe was only 10-15 percent of the modern one, i.e. 1-2 billion years after the Big Bang.

And these three large gas clouds do contain a lot of carbon and oxygen, but they have practically no iron. On the basis of which scientists conclude that these are really the remnants of supernovae that have flared up at the very beginning of the Universe. By the way, some very old stars in our Galaxy have a similar composition, from which astronomers conclude that they are second-generation luminaries.

An interesting point is also how scientists have found these clouds. Quasars helped them in this. These supermassive black holes, which are very far away from us, are in the phase of active absorption of matter, part of which is converted into radiation. This light flies through the entire Universe and on its way passes through matter, which becomes visible due to this. 

According to

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