What Are Supernovas — Powerful Explosions from Interstellar Space?

Do you know things and events in space can be much more mighty than you think? One of the instances is supernovas (a.k.a. supernovae), which are explosions from space. In fact, a single supernova can kill all living organisms within 50 light-years of the epicenter. (What If, 2021)². So, let’s explore that unusual phenomenon today!

What Can Trigger Supernovas?

How will an event that immense form in space? Well, some methods can trigger supernovas. The most well-known one is when massive stars reach the end of its life. Each of these stars contains at least 8 Solar masses of matter. Anything below will eventually become a white dwarf.

Firstly, you have to understand a star is in a continuous struggle between its mass and the outward force caused by the pressure. If that balance breaks, the star will either shrink or expand, or the condition below happens.

When a star runs out of hydrogen, it will fuse helium, carbon, oxygen, and so on. However, when this happens, pressure builds up at the core of the star. Eventually, the core will reach the Chandrasekhar limit: about 1.4 Solar masses. That’s the real limit, compared to the estimated one of 8 Solar masses for an entire star. When the core reaches that mass and becomes too massive to be stable, the gravitational forces override the outward force, collapsing the star very quickly.

Upon the collapse of the core, the outer layers bounce back ferociously, creating an incomprehensibly powerful blast and a nebula that quickly inflates. The remaining core, which has a powerful gravitational pull, becomes a neutron star (or even a black hole if the original star is heavier). This is the result of a Type II Supernova.

A White Dwarf Can, too

But, do you know that less massive objects like white dwarfs can be the cause of a supernova? Well, that’s the truth! Nevertheless, this only occurs when a white dwarf has a companion (another star in the same star system).

Remember that white dwarfs have enormous gravitational pulls, too, as they are Earth-sized but sometimes as heavy as the Sun. Therefore, the white dwarf will suck on stars that get close to itself to be more massive.

However, the white dwarf is probably destroying itself. If the companion is massive enough, the Chandrasekhar limit will be exceeded if the white dwarf absorbs enough matter. That will lead to a Type Ia Supernova.

How Much Energy can It Make?

Now, we’ve understood the scale of supernovas (of mass), but how much energy can they produce? According to an article from the Georgia State University⁵, a supernova can produce as much energy as the Sun produces in its entire lifetime! Moreover, some even more powerful supernovas exceed that energy level.

In the actual energy, a lot of it turns into light. A supernova can outshine galaxies for weeks or even months! Furthermore, some supernovas are found billions of light-years away, proving their energy levels.

A lot of the light emitted by supernovas are invisible — they are ultraviolet light, X-rays, or even gamma-rays. The resulting excessive amounts of high-energy electromagnetic radiation is lethal to everything within 50 light-years, as mentioned in the first section.

Why Are They Essential for Life

Despite how destructive supernovas are, you should be grateful that they happen. If they don’t, life as we know it won’t exist.

Because of the fierce compression, even elements heavier than iron fuse together, which shouldn’t even be in the star’s massive core. Therefore, a lot of essential elements are made, including iodine, molybdenum, zinc, etc. That makes supernovas the primary source of elements heavier than iron.

What’s more, these explosions are tied to us even more closely than constructing these elements. The blast creates a shock wave, which can help the formation of new stars. If the Universe doesn’t shake at all, the star formation will be much slower. (National Geographic, n.d.)⁶

On the Scientific Level

Other than the bare necessities, supernovas help humanity on the scientific level. For example, we can easily discover new galaxies by just looking at a supernova if we’re lucky enough. We can find out distinct features that are very useful in future explorations. As mentioned earlier, supernovas outshine their host galaxies, making the galaxy itself easier to discover.

Furthermore, we have to know which stars are about to explode by looking at the original stars of supernovas to be ready of any nearby supernova.

In fact, the closest supernova candidate that may explode in the future is IK Pegasi B, a white dwarf 150 light-years from Earth. Therefore, we don’t have to worry about that unless the supernova will be too powerful or closer to us when it erupts. (EarthSky, 2018)⁷.

Conclusion

So, we’ve discussed supernovas in this article. Are you impressed by this astronomical phenomenon? Let us know in the comments. Also, check out the resources used in this article to learn even more.

References and Credits

1. (2019, October 23). What Is a Supernova? | NASA Space Place – NASA Science for Kids. Retrieved February 10, 2021, from https://spaceplace.nasa.gov/supernova/en/
2. What If. (2021, January 1). What If a Supernova Exploded Close to Earth? – YouTube. Retrieved February 10, 2021, from https://www.youtube.com/watch?v=Uyh4JP1ELpY
3. (2012, January 19). The Chandrasekhar Limit: The Threshold That Makes Life Possible | NOVA | PBS. Retrieved February 10, 2021, from https://www.pbs.org/wgbh/nova/article/the-chandrasekhar-limit-the-threshold-that-makes-life-possible/
4. (2020, September 23). Type Ia Supernova – Exoplanet Exploration: Planets Beyond our Solar System – NASA Exoplanets. Retrieved February 10, 2021, from https://exoplanets.nasa.gov/resources/2172/type-ia-supernova/
5. (n.d.). Supernovae. Retrieved February 10, 2021, from http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/snovcn.html
6. (n.d.). Supernovae Information and Facts | National Geographic. Retrieved February 11, 2021, from https://www.nationalgeographic.com/science/space/universe/supernovae/
7. (2018, May 11). What’s a safe distance between us and a supernova? | Astronomy Essentials | EarthSky. Retrieved February 11, 2021, from https://earthsky.org/astronomy-essentials/supernove-distance
8. Andrea Thompson. (2018, February 9). What Is a Supernova? – Discovery, Death and Explosions | Space. Retrieved February 11, 2021, from https://www.space.com/6638-supernova.html

Image Credits: NASA Space Place, Canva, NASA’s Eyes