When the brightness of the star Betelgeuse dropped dramatically a few months ago, some observers suspected an impending supernova ̵
The life of stars with a mass ten times the mass of our sun ends with a supernova, a colossal stellar explosion. This explosion leads to the formation of iron, manganese and other heavy elements.
In layers of manganese crust that are about two and a half million years old, a research team led by physicists at the Technical University of Munich has now confirmed the existence of both iron-60 and manganese-53.
“Elevated concentrations of manganese-53 can be considered ‘smoking smoke’ – the best proof that this supernova really happened,” says first author Dr. Gunther Korshinek.
While a very close supernova could do enormous damage to life on Earth, it was far enough away. This only caused the cosmic rays to accelerate for several thousand years. “However, this can lead to increased cloud formation,” says co-author Dr. Thomas Feesterman. “It may have something to do with the Pleistocene, the Ice Age, which began 2.6 million years ago.”
Manganese is usually found on earth as manganese-55. Manganese-53, on the other hand, usually originates from cosmic dust similar to that in the asteroid belt of our solar system. This dust is constantly falling on the ground; but we seldom perceive larger spots that glow like meteorites.
New sediment layers, which accumulate year after year on the seabed, preserve the distribution of the elements in manganese crusts and sediment samples. Using accelerating mass spectrometry, the team has now found both iron-60 and elevated levels of manganese-53 in layers that were deposited about two and a half million years ago.
“This is an ultra-investigative investigative analysis,” Korsinek said. “We’re talking about just a few atoms here. But acceleration mass spectrometry is so sensitive that it even allows us to calculate from our measurements that the star that exploded must have been about 11 to 25 times the size of the sun. “
The researchers were also able to determine the half-life of manganese-53 from comparisons with other nuclides and the age of the samples. The result: 3.7 million years. To date, there is only one measurement for this purpose worldwide.
Supernova iron found on the moon
G. Korschinek et al, Mn53, produced by a supernova on Earth, Physical examination letters (2020). DOI: 10.1103 / PhysRevLett.125.031101
Provided by the Technical University of Munich
Quote: Starburst near Earth (2020, September 30) retrieved on September 30, 2020 from https://phys.org/news/2020-09-stellar-explosion-earth-proximity.html
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