A team of researchers recently observed stars previously hidden behind a cluster of galaxies, revealing a previously unknown part of the history of the universe.
Tl;dr
- Scientists have discovered 44 stars hidden behind the galaxy cluster Abell 370, 6.5 billion light years away, thanks to gravitational lensing.
- These stars, red supergiants, are difficult to observe due to the dust that surrounds them, but were captured by the James Webb Space Telescope.
- This discovery helps us learn more about star formation and dark matter, offering clues about the structure of the universe at that time.
A fascinating discovery at the heart of the Dragon Arc
Astrophysicists from Durham University made the major discovery in the Dragon Arc galaxy, a still-mysterious region of the cosmos. This advance is part of an international research project and marks a turning point in the understanding of the universe. What makes this discovery particularly exciting is that it comes during a key period in the history of the universe, known as “cosmic noon.” It was during this period, the heart of the cosmic age, that the majority of stars in the universe were formed. This epoch is crucial for understanding the evolution of galaxies and stars through time.
The gravitational lensing effect: a window into the invisible
The galaxy cluster Abell 370, located between Earth and the Dragon Arc, plays a key role in this discovery. Through a phenomenon known as gravitational lensing, the enormous mass of this galaxy cluster bends and amplifies the light from the Dragon’s Arc, making stars visible that would otherwise have escaped our observation. This effect acts like a “cosmic mirror” on a gigantic scale, allowing astronomers to peer into very distant objects that are invisible under normal conditions. The magnified images of these stars were captured by the James Webb Space Telescope, providing scientists with a unique opportunity to analyze these distant stars.
-Red supergiant stars: an observational challenge
The newly observed stars are red supergiants, a category of stars that is particularly difficult to study due to the large amount of interstellar dust that surrounds them. This dust makes their observation complex with traditional instruments, making their detection all the more important. Scientists, notably Professor Mathilde Jauzac, explain that this discovery opens a window of observation on these stars which were until then invisible due to the obscuration of dust. This observation could provide valuable information on how these stars enriched the universe at the time of their formation and their role in the evolution of cosmic matter.
A new era for dark matter research
In addition to the scientific impact of the discovery of stars, this study also allows us to know more about dark matter, this mysterious substance which makes up a large part of the universe. The gravitational lensing effect used to observe stars also allows us to better understand the distribution of dark matter in the Abell 370 cluster. By analyzing the properties of these stars, researchers can obtain information about the mass of the cluster. of galaxies and the amount of dark matter it contains. These new data offer new perspectives to better understand this fundamental component of the universe which still escapes our complete knowledge.
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