Is a supernova explosion within 160 light-years dangerous? Mass extinction probability further than traditionally assumed | sorae portal site to space

A research team led by Ian Brunton of the University of Illinois at Urbana-Champaign has announced research findings that it has discovered a previously unknown risk of a supernova explosion. The researchers said that a supernova that originated six times farther away than previously thought could have a significant impact on the planet’s atmosphere.

Supernova explosions, which are said to occur in binary star systems containing massive stars with masses equal to or greater than eight suns and white dwarfs, emit powerful electromagnetic waves such as gamma rays and high-energy particles. According to research results published in 2003, if a supernova explosion occurs within 26 light years (8 parsecs) of Earth, life on Earth will be destroyed by atmospheric effects accompanied by ozone depletion.

This time, the research team used data from observational satellites such as NASA’s Chandra, Neil Gereels Swift, Neustar, and the European Space Agency’s XMM-Newton to study the Large Magellanic Cloud. We analyzed 31 supernovae detected from 1970 to 2019, including supernova SN 1987A and its successor.

[▲بقايامستعرأعظممنالمستعرالأعظم”SN1987A”(Credit:NASA/CXC/UnivofIllinois/IBruntonetal)]

The team’s analysis showed that planets can be catastrophically affected even when the supernova is about 160 light-years (50 parsecs) away. If the planet’s environment were the same as Earth’s, most of the ozone layer would likely be lost. The “dangerous distance” indicated by the previous research was about 26 light-years away, as mentioned above, so even a supernova about six times farther away could be life-threatening.

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According to the research team, the newly identified danger is represented by X-rays. If there is dense gas around the object that caused the supernova, a large amount of X-rays will be emitted through the interaction between the shock wave from the explosion and the gas. X-ray emissions can last for decades, and the arriving X-rays can dramatically alter the chemistry of a planet’s atmosphere, producing enough impact to cause a mass extinction.

【▲ Artist’s impression of a supernova seen relatively close to an Earth-like planet (top) and after being affected by a large amount of X-rays from the supernova explosion (bottom). Image credit: NASA/CXC/M. Weiss

Fortunately, it is said that there are no stars around the solar system that could cause such damage, but in the past the situation may have been different. Based on evidence such as radioactive isotopes of iron collected around the world (thought to have fallen to Earth after being fired by a supernova explosion) it is estimated that the supernova originated at a distance of about 65 to 600 light-years, because this distance overlaps in part with the “hazardous distance”. X-rays shown in this study.

According to the Chandra X-ray Center, which operates the Chandra X-ray Observatory, the solar system is currently a “local bubble” in which low-density, high-temperature gas is surrounded by low-temperature gas. It is about several hundred light years across. The Local Bubbles are believed to have formed approximately 14 million years ago through a series of star formation activities and supernova explosions that occurred in the center of the region. that time than it is today.

[▲ فيديو تعليقي لنتيجة هذا البحث بواسطة مركز شاندرا للأشعة السينية (شرح باللغة الإنجليزية)]

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Although this evidence does not directly link past mass extinctions on Earth to supernova explosions, it does suggest that supernova-like explosions have impacted Earth since the birth of the solar system.

‘More research on supernova-derived X-rays is important because it affects not only understanding the life cycle of stars, but also areas of astrobiology,’ said Brian Fields of the University of Illinois, who was involved in the research, and said of the importance of future research. Paleontology, earth and planetary sciences.

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• Image credit: Science: NASA/CXC/Univ. Illinois/I. Brunton et al.; Illustration: NASA/CXC/M. Weiss
• Chandra X-Ray Centre – New stellar danger to planets identified by NASA’s Chandra
• Illinois News Bureau – A new stellar hazard to planets identified by NASA’s Chandra program
• Brunton et al. X-ray supernovae: Threats to terrestrial biomes

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