“Betelgeuse” - No, not the film but rather a red supergiant star located 640 light-years away within the constellation of Orian that may be going supernova sooner than we’d previously predicted.
Supernovae are essentially the death of stars. They occur when a star uses up all of its fuel during nuclear fusion and collapses due to a major drop in pressure. Now, what exactly is nuclear fusion and what acts as fuel? In simple terms nuclear fusion is the combination of elements at high temperatures in order to create larger elements on the periodic table and exert massive amounts of energy. Hydrogen is the simplest and most abundant element in our universe, containing only a single proton. When hydrogen undergoes nuclear fusion, the element of helium is created which contains two protons. So therefore, you’d think that when you fuse two helium atoms, you’d create lithium, an element with three protons. However, this is not the case, and this is what makes Betelgeuse interesting.
Stars take an exceedingly long time to exhaust their helium reserves and this in turn makes it almost impossible to predict how long they will take to go supernova. Yet in recent studies it has been discovered that Betelgeuse has indeed finished fusing helium and has moved onto the fusion of carbon (A much shorter process.) Helium fuses to create carbon via a 3-body reaction called the triple alpha process which only occurs at very high temperatures and densities such as within a star. The triple alpha process is when two atoms of helium fuse together to create a radio-decaying atom of beryllium (which contains four protons.) If another atom of helium is able to fuse with this beryllium before it fully decays then it is able to form a stable atom of carbon (with six protons). Carbon to carbon fusion then continues within the star to form heavier elements such as nitrogen, oxygen, neon, aluminium and eventually iron. Iron, however, is unable to conduct fusion with itself as it’s very heavy and uses up too much energy from the star which ultimately leads to the stars collapse and supernova.
Due to this recent discovery, scientists have been able to predict that Betelgeuse is likely to go supernova within the next 10-100 years. Although, interestingly the event has probably already happened, and we just don’t know about it yet as the light from the explosion takes 640 years to reach earth. Now what will happen within the next century when this supernova explosion finally reaches Earth?
The explosion would release a burst of ultraviolet radiation which could temporarily consume the ozone layer, however it would not last long enough to cause any major harm to the environment or life. The light from the explosion would be as bright as a full moon on Earth, making for an incredible spectacle to be enjoyed by astronomers and stargazers alike.
One fear that many have is the possibility of Betelgeuse forming a blackhole after collapse, as this often happens to stars going supernova. Despite Betelgeuse’s enormous size, it is still not large enough to collapse with the gravity needed to form a black hole and therefore this shouldn’t be something we have to worry about.
Image from Forbes