A supernova is a powerful star explosion that would be extremely bright and hot. If a supernova ever did happen and our sun exploded, only the side facing the sun would boil away due to the heat. A supernova can happen if a star grows too big, at least five times the size of our sun, it can die instantly. When the star runs out of energy, the internal pressure drops, and gravity takes over, causing the star to explode. If the supernova is more than ten times the size of our sun, it can lead to the creation of black holes. The type of supernova that we will be focusing on will happen when two stars collide, and one of the stars is a small white dwarf. Astronomers do not usually worry about supernovae since it is not common, and the closest stars that can explode as a supernova are hundreds and thousands of light-years from Earth.
What would happen to Earth?
If the sun, our primary energy source, ever exploded as a supernova, it is safe to say the consequences would be significant. Earth’s temperature is expected to be 15 times hotter than the sun’s average temperature. All the planets, including Earth, would not stay in orbit because the sun’s mass freed them. Not all stars in the universe would explode as a supernova, and our sun is not one of them. According to scientific literature, Earth’s closest safe distance to a supernova is approximately 50 to 100 light-years away. However, if a supernova did happen and were less than 50 light-years away from Earth, we would all be extinct. Earth has an ozone layer that protects us from the ultraviolet rays from the sun. A supernova would destroy that layer which would impact our whole environment. There would not be enough oxygen in the air, and our respiratory system would shut down. Nature and animal life would also become extinct because the natural resources are gone. Even if the supernova occurred a little further, radiation would enter the Earth’s atmosphere causing hundreds of mutations that would change our everyday living. Not to mention, radiation also affects the climate and weather.
Has a supernova ever happened?
The most recent supernova to be recorded happened in 1987 and was 168, 000 light-years away from Earth. Despite being far away from Earth, this supernova was visible to the naked eye, Supernova 1987A. Johannes Kelper, an astronomer who discovered three major planetary motions, also documented a supernova in 1604. This supernova was close to Earth at 20, 000 light-years away, it was so bright that it was visible in daylight. It might have caused small changes in the Earth, but nothing was recorded because of how far away it was located.
Are there any supernovae located 50 to 100 light-years of Earth?
There are many types of supernovae in the universe. Type I is caused by the collapse of a white dwarf star. Again, it is hard to determine how many are within 50 light-years of Earth because of their small sizes. The nearest potential Type I supernova is 150 light-years of Earth. Type II supernova is an aging star that collapses, however because of the massive size, it is not possible within 50 light-years. IK Pegasi A can start to expand in size to a massive red giant, it is a main-sequence star (different from our sun), which then IK Pegasi B can accrete matter and grow in size. Once IK Pegasi B gets large enough, it can collapse on itself and explode as a supernova.
Will a supernova ever happen?
Supernovae have happened in the past, but some are predicted to happen in the future. In 2008, astronomers spotted a star near the Scorpio constellation, a double star appeared and were so close to each other they were touching. Astronomers noticed that the orbital period was decreasing, which foreshadowed that the two stars would collide. As predicted, in 2008, the two stars emerged into one after a red spot occurred in that location. Astronomers predicted that the binary system was responsible for the two stars merging. History repeats itself, astronomers predicted that in 2022, the red nova exploding star would appear and be visible to the naked eye. Studies from 2019 showed that the star was 1800 light-years away and had an orbit speed of 11 hours. Unfortunately, other studies by astronomers proved the theory to be false, and we will not be able to see the stars explode. From many studies and research, I can conclude that no known and big star is expected to explode as a supernova in our lifetime. The future is always a possibility.
Written by: Amber Truong
Sources:
Berman, B. (2019, January 29). A New Star in the Night Sky in 2022. Old Farmer’s Almanac. https://www.almanac.com/new-star-night-sky-2022#:%7E:text=This%20is%20exciting%20space%20news,naked%20eye%20nova%20in%20decades.
E. (2018, May 11). What’s a safe distance between us and a supernova? | Astronomy Essentials | EarthSky. EarthSky | Updates on Your Cosmos and World. https://earthsky.org/astronomy-essentials/supernove-distance/#:%7E:text=A%20supernova%20is%20a%20star,the%20sun%20would%20boil%20away.&text=Clearly%2C%20the%20sun’s%20distance%20%E2%80%93%208,away%20%E2%80%93%20isn’t%20safe.
What Is a Supernova? | NASA Space Place – NASA Science for Kids. (2021, July 23). NASA. https://spaceplace.nasa.gov/supernova/en/
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