One of the most spectacular events of our universe is the Supernova explosion. It is probably THE MOST powerful explosion known to humans. So, what really is this supernova? Is it dangerous? How powerful is the explosion? How frequently does it occur? There are many such questions that keep coming to us and today, we will make an attempt to answer these questions through this list of 30 interesting supernova facts.
Supernova Facts 1-10
1. Supernova is nothing but a stellar explosion. To put in other words, it is actually an explosion of a star.
2. So massive is the explosion that for a brief amount of time, the explosion actually outshines the entire galaxy in which it explodes.
3. Whenever an explosion takes place, energy is emitted and supernova is no exception. The amount of energy radiated in one supernova explosion is equal to the amount of energy that has been radiated by our Sun so far plus the energy that it will radiate for the rest of its life.
4. A supernova is so bright that it literally takes weeks and sometimes months for the brightness to fade away.
5. During this explosion, luminous radiations are burst out and almost all of the material of the exploding star is expelled in outer space.
6. The material that is expelled from the exploding star travels at a very high speed of 30,000 kilometers in one second.
7. This explosion sends out a shockwave in nearby outer space. The outer space that we keep saying is actually referred to as interstellar medium which is defined as matter that exists in space between stars within a galaxy.
8. As this shockwave travels through this interstellar medium, the gas and dust from the exploding star are bound by the shockwave and it continues to expand. This expanding structure is known as supernova remnant.
9. Every time a supernova explosion takes place, the interstellar medium is enriched by elements of higher mass.
10. Not every star explodes. For instance, our Sun (which is a star) will never explode. Stars that are 10 to 100 times bigger than our Sun eventually explode and create a supernova explosion.
Supernova Facts 11-20
11. When a massive star eventually runs low on hydrogen (the fuel that is converted to helium through fusion reaction), the remaining hydrogen pushes outwards towards the shell, surrounding a helium core.
12. When the hydrogen moves to the outer shell around the helium core, the star becomes unstable and the outer shell is enormously inflated, converting the star into a red giant.
13. At this stage, the hydrogen in the outer shell of the red giant still fuses into helium producing thermal energy which wants to expand the star.
14. The helium core on the other hand exerts gravitational pull attempting to crush the star.
15. When the remaining hydrogen burns out, gravitational pull of the helium core wins and helium atoms start fusing to form iron atoms, thus forming an iron core inside the helium shell.
16. Eventually the core becomes too heavy and cannot withstand its own gravitational pull and the core starts collapsing. This is when the star explodes to form a supernova.
Till now we have learned about how supernova happens in case of a single giant star. There is however another way in which a supernova explosion can take place. Let us find out how:
17. Supernova explosions also take place in what is known as binary star systems. A binary star system consists of two stars one of which is a carbon-oxygen white dwarf. The other is known as the companion star.
18. In this type of star system, the white dwarf (which is actually a star close to its life’s end and has used up most of its nuclear fuel, eventually collapsing into a small size almost similar to the size of earth) is known to be a thief. This white dwarf steals or draws matter from the companion star. This happens because of the enormous gravitational pull of the white dwarf.
19. At some point, the white dwarf ends up accumulating too much matter.
20. This excessive amount of matter eventually causes the star to explode violently, resulting in a supernova explosion.
Supernova Facts 21-30
21. Supernova explosion shoots out billions and billions of atoms in every possible direction and they form colorful nebulae.
22. The exploding star may end up as a black hole and a nebula. However, if the star isn’t really a big one, the supernova explosion will end up as a neutron star and a nebula.
23. The expanding supernova remnant can produce enough kinetic energy that can compress the highly dense molecular clouds in the interstellar space and form stars.
24. Supernova explosions or supernovae are the primary sources of metals in interstellar space and till date they remain known as the only dominant mechanism for the distribution of heavier metals that are usually formed inside a star during its life through nuclear fusion reaction.
25. The last known supernova explosion in our galaxy Milky Way was SN 1604. Astronomer Johannes Kepler started observing the supernova on 17th October 1607 and hence, it is named as SN 1604. The latest observed supernova was in Andromeda Galaxy in 1885 and is known as S Andromedae.
26. The first stars of our universe became supernovae around 14 billion years ago. Our sun is not big enough to become a supernova.
27. Elements like carbon, iron, silicon, nitrogen and oxygen that we find on Earth actually came from a supernova.
28. During the explosion, elements like uranium and gold are formed because of the extremely high temperature (millions of degrees) caused by the explosion.
29. In 1054 AD, Islamic and Chinese astronomers observed and documented a supernova. It was so bright that it was visible in broad daylight.
30. The Crab Nebula that we see today is actually a result of the supernova explosion of 1054 AD.