[Physics Class Notes] on Supernova Pdf for Exam

Supernova is the result of the explosion that occurred by the dying massive star. As a result, tons of energy got released into interstellar space.

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When a massive star burns the nuclear fuel inside it, the interstellar space becomes the hottest, and light spreads all around. 

So, basically, a supernova is the most powerful and light-emitting stellar explosion that occurred most likely 10,000 – 20,000 years ago lastly.

In this article, we will discuss exploding stars, types of supernova – type 1a supernova, and type 2 supernova in detail.

Exploding Stars

We all know that gases like hydrogen and helium make most of the gases in interstellar space and that the place where stars are born. We see that besides hydrogen and helium, there are other gases like carbon, oxygen, and iron also exist.

Stars are huge balls of these gases and take millions of years in their formation, and eventually, they become massive, while storing a huge quantity of energy and fuel within themselves.

A time comes when these stars start burning their nuclear fuel and their core becomes hot. 

Now, these massive stars become five times bigger than the Sun, they give a fantastic bang; during this big bang, a lot of heat and luminous energy is released into space. Soon this star releases all of its fuel and becomes dwarf due to the runaway of all its energy, it dies. Eventually, this last hurrah of the dying star is Supernova. 

Now, a time comes to understand what a supernova is.

What is a Supernova?

From the above introduction, we read that supernova is a powerful and luminous stellar explosion. 

This transient and mighty astronomical event occurred during the last evolutionary stages of a massive star or when a white dwarf led into runaway nuclear fusion.

The original object, viz: the progenitor either collapses to a neutron star or a black hole gets completely destroyed. The peak optical luminosity of a supernova is in contrast to that of an entire galaxy before fading over several days/months.

Now, let’s understand the types of supernova.

Types of Supernova

The two following types of supernova are as follows:

1. Type 1a Supernova

2. Type 2 Supernova

3. Real supernova

Type 1a Supernova

• This type of nova takes place in binary star systems. In this, one star is classified as a white dwarf.

• This white dwarf accretes material from its large counterpart, accumulates mass, and this incites a chain nuclear reaction.

• After culminating in the star, reaching the critical density, it explodes in a type 1a supernova. Beams of gamma rays spread in space.

Type 2 Supernova

Type 2 is known as the second type of supernova. It occurs at the end of the lifetime of a star. As the star releases its entire fuel, some of its mass flows into its core. 

A time comes when the core becomes so heavy that it cannot handle its own gravitational force. Therefore, the core collapses and results in the giant explosion of a supernova.

Steps of How Type 2 Supernova Occurs:

• Stars after losing the ability to fuse heavy elements, also lose the ability to retain gravitational equilibrium. After this, the core collapses.

• This core rebounds in quick succession subsequently releasing the outer layer of gases into the atmosphere. Hence, a nebula formation occurs.

• After the dust settles, a neutron star or a black hole is left behind, which hinges the Earth’s star.

Besides the two types of supernova, there is another supernova and that is a real supernova, as classified by AI with unprecedented accuracy.

Real Supernova

Artificial intelligence is trying to classify real supernova explosions without the traditional employment of spectra. 

However, the astronomers developed a software program that classifies various supernovae based on their light curves, or how their brightness varies over time. 

A postdoctoral researcher at the CfA and lead author on the first of two papers published in The Astrophysical Journal named Griffin Hosseinzadeh said that they have approximately 2,500 supernovae with light curves from the Pan-STARRS1 Medium Deep Survey, and 500 among these supernovae with spectra that can be utilized for classification.

Do You Know?

• The first supernova was seen in 1604. The amazing thing was, it reached the Earth planet only.

• Supernova is 13,000 light-years away from the Earth.

• Lastly, a supernova explosion formed a Vela Supernova Remnant around 20,000 years ago. The earliest supernova was HB9 that was recorded by a few Indian observants in around 4500 ± 10,000 B.C.

• Supernova is radiant and it emits more energy at the peak of the explosion than a whole galaxy, like the Milky Way, with a hundred million stars typically emits. A supernova emits the same energy in a few months that the Sun will emit in its entire life.