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What Is a Supernova?

Using Slooh’s Online Telescope and integrated NGSS aligned Quest learning activities, you can capture your own images of massive stars throughout their life cycle and make an infographic like the one above. Out With a Bang is one of 60+ curriculum-aligned STEM Quest learning activities on Slooh for students 4th grade to college.

Slooh’s Online Telescope:

For Everyone For Educators

If you are an educator looking for fun, interactive ways to teach NGSS: HS-ESS1-1, HS-PS1-8, and HS-ESS1-3, as well as other standard curriculum codes related to astronomy, keep reading to the end for more information on the Out With a Bang Quest and ways to easily integrate Slooh into your classroom.


What Is a Supernova?

Most events in astronomical evolution take a very long time to happen, occurring over periods of time longer than human history. Supernovae are an exception to that rule. These spectacular and violent deaths of high-mass stars, which are some of the brightest events in the universe, sometimes even outshining entire galaxies, happen within seconds and fade away just a few years later.

For most of a star’s life, the energy produced in its core provides an outward pressure, keeping the star in equilibrium and preventing gravity from causing the star’s collapse. Once a star has only iron left in its core, having used up all of its fuel, no energy can be produced. Without energy from the core, the force of gravity takes over, causing the star to collapse incredibly quickly.

When the matter from the star's outer layers crash down onto the core, there is a massive exchange of energy from this matter to the core's iron. This exchange causes the iron to fuse together to create heavier metals and elements such as gold, silver, and uranium. The process that does this is called inverse fission. In fission, a single nucleus is broken apart, which generates energy and two smaller nuclei. The inverse fission process, on the other hand, starts with two smaller nuclei (the iron) and an input of energy (the layers falling on the core) and results in the heaver nuclei (gold, silver, uranium, etc.) forming.

As the layers bounce off the star's core, all of the newly formed matter is launched into space, creating a huge explosion. The ejected debris includes both the new heavy metals and elements as well as all those formed during the star's life. These materials seed new stars, planets, and everything else we find in space. Every element found on Earth, except hydrogen, was formed in the cores of stars long ago. That includes the carbon, oxygen, and nitrogen atoms in our very own bodies. As astronomer Carl Sagan said, “The cosmos is within us. We are made of star stuff."

Supernovae in History

The earliest recorded supernova was noted by Chinese astronomers in 185 CE. In the Book of the Later Han, what we now know as a supernova was described as a guest star because it appeared and, after some time, disappeared again. It was said to be visible in the sky for eight months.

In 1054 CE, many cultures around the world saw what they believed to be a bright star that appeared suddenly in the sky, having not been there the night before. It was visible during the day, though it was not as bright as the full moon. Then, after a brief time, it faded away. This was the supernova event that led to the creation of the Crab Nebula, which was first viewed through a telescope in 1731.

The Crab Nebula

What's Left After a Supernova?

When supernovae send out their shock waves of energy, material is swept up from the interstellar medium. This material and the material ejected from the star make up the supernova remnant, which expands and diffuses through space for several hundred thousand years before being fully dispersed. Before disappearing, these giant clouds are the birthplace of new stars and planets. The remnant of a supernova looks like a colorful bubble of gas in space. When viewed in detail, it’s possible to see vein-like structures, with denser regions forming knots of gas and thin filaments connecting them. Supernova remnants are not always optically visible, but they are strong emitters of X-ray and radio waves.

Veil Nebula supernova remnant (East)

While the supernova remnant begins to form, the star’s core continues to contract, and it eventually becomes one of two bodies: a neutron star or a black hole. A neutron star, formed when a star of at least eight solar masses collapses, is made of 95% neutrons and 5% protons. These particles are held together by the strong nuclear force, the same force that holds the nuclei of atoms together. The neutrons are created by a process called neutronization, where the incredible gravitational pressure squeezing the star's iron core destroys all of the atomic nuclei until all that is left are neutrons and protons. In the process of forming a neutron star, a star’s core collapses from the size of the Earth to the size of a city! Neutron stars are the densest large-scale objects in the universe; they contain as much material as the entire solar system. Imagine packing every human being into a space the size of a sugar cube – that’s how dense a neutron star is! The Crab Nebula discussed above has a particular type of neutron star, a pulsar with a diameter of only 29 kilometers, embedded in it. A pulsar is a neutron star that rotates extremely quickly and emits a beam of radio waves.

Black holes form when a massive star dies and forms a neutron star, but that neutron star is too massive to balance its gravity. When there are at least 1.4 solar masses of material in the space of a neutron star, its gravity is so strong that even neutrons are broken up, causing all of its matter to collapse into a single point known as a singularity. A black hole has such a strong gravitational force that it causes everything near it to fall in and never escape. That even includes light, which is why we can’t see black holes! Because no light can escape a black hole, scientists have to look at the behavior of nearby objects to identify them.


More About Slooh's Out With a Bang Quest

In this quest, you will use Slooh's telescopes to capture images of higher mass stars at different points in their life cycle in order to explore the life and death of stars more massive than the Sun. This quest will culminate with the construction of a model of the lifespan of more massive stars using your images and text explanations.

Learning Objectives

By the end of this Quest, students will be able to answering the following questions:

  • How do stars with masses larger than the Sun form?

  • What is fusion, and what happens when this takes place in larger main sequence stars and how does that affect what happens in the star's core?

  • How do stars of masses larger than the Sun end their lives? What happens to the remnant stars?

  • What is the difference between direct and inverse relationships?

Vocabulary Words

Standards Addressed

NGSS Performance Expectations

​HS-PS1-8, HS-ESS1-1, HS-ESS1-3


​RST.9-10.1, RST.9-10.2, RST.9-10.3, RST.9-10.4, RST.9-10.5, RST.9-10.9, RST.9-10.10, WHST.9-10.2.D, WHST.9-10.2.E


HSN.Q.A.1, HSN.Q.A.2

Related Slooh Quests

  1. Stars Like Ours

  2. There Goes the Sun

  3. Our Radiant Star

More About Slooh’s Astronomy NGSS Aligned Learning Activities

Slooh’s Online Telescope is a learning platform designed to support any educator in teaching astronomy to meet NGSS requirements by collecting and analyzing real-world phenomena. No previous experience with telescopes is necessary to quickly learn how to use Slooh to explore space with your students.

You can join today to access Slooh's Online Telescope and all 60+ Quest learning activities if you are able to make astronomy a core subject of study for the semester or year. If you only have a few weeks to study astronomy, we also have a curriculum designed to fit your busy academic schedule and budgetary limitations. To learn more about our offers, click here.