Discovery of a star 100 times more distant than all those seen so far

Découverte d'une étoile 100 fois plus éloignée que toutes celles observées à ce jour

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Astronomers have discovered, by accident, a star located more or less $ 9.3 billion light-years from Earth, is about one hundred times more distant than any that had previously been observed.

Officially called MACS J1149-2223 Lensed Star 1, but nicknamed Icarus, the star, a blue supergiant, was discovered by chance in 2016, then, that astronomers have studied distant galaxies using the Hubble space telescope.

The discovery of the star allows you to go back in time and see one of the first generations of stars in the universe, whereas the Big Bang would have occurred approximately 13.8 billion years ago.

“To discover such phenomena is very important to advance our knowledge of the composition that is fundamental to the universe,” said Tommaso Treu, co-author of the study, conducted by a team from the university of California at Los Angeles who has been published at the beginning of this month in the journal “Nature Astronomy”.

To this day, the stars most distant ever observed were approximately 90 million light-years from the Earth. Those located further away remained obscured by other celestial objects, such as galaxies and supernovae, and remained undetectable by telescopes at the disposal of scientists.

The team of researchers who discovered Icarus explained that they had a lot of luck. In fact, even if the supergiant is thousands of times brighter than our sun, it remains far too distant to be visible from the Earth. Gold, a cluster of galaxies is interposed between the Earth and Icarus, forming a gravitational lens. This phenomenon occurs when a mass interposes itself between a star and its observer, making bending light with its gravitational field at the point of the amplifier.

As a bonus, another star would also have contributed to amplify the light emitted by Icarus, to the point of making it 2000 times brighter than in reality.