THE MOST DISTANT NORMAL STAR EVER DISCOVERED USING COSMIC LENS, CAPTURED BY ASTRONOMERS
NASA, ESA, and P. Kelly (University of Minnesota)
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A phenomenon known as gravitational lensing—which is the process by which light is bent, or deflected, due to the matter existing between an observer and a distant light source. This was not enough in this case to produce a result, however. Because of interaction with a very large nearby cluster, the star, not visible in 2011, was magnified to a size of more than 2,000 times, which in the end made it detectable. This, no doubt, brings an entirely new meaning to the idea of the stars aligning.
NASA initially employed gravitational lensing to plot the locations of dark matter existing in various galaxy cluster, and thus answer more questions about the elusive pockets of matter that exist throughout the Universe, with the ultimate goal being to “better trace the history of star formation in the universe, over the past 13 billion years”
Details about the landmark event appear in a paper, titled “Extreme magnification of a star at redshift 1.5 by a galaxy cluster lens”, which was published online yesterday in Nature Astronomy. The star is named MACS J1149 Lensed Star 1 (LS1), or its more informal name of Icarus.
The sighting of Icarus exceeds the normal capabilities of gravitational lensing in two fundamental ways:
• A distance of 100 million light years is typically the farthest observable distance.
• Magnification occurs at a rate that hovers around but usually doesn’t exceed 50 times.
Paper co-author and UC Berkeley Astronomy Professor Alex Filippenko said of the find
“There are alignments like this all over the place as background stars or stars in lensing galaxies move around, offering the possibility of studying very distant stars dating from the early universe, just as we have been using gravitational lensing to study distant galaxies. For this type of research, nature has provided us with a larger telescope than we can possibly build!”
The goal of these missions is to deepen our level of understanding of the cosmos, both adding to the never-ending supply of information that is being generated and allowing scientists to challenge and adapt old assumptions about the origins of life in the Universe. In this instance alone, the idea that dark matter is composed of various primordial black holes, it seems has been firmly put to rest.
source:interestingengineering
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