A supernova can be compared to a cataclysmic explosion in the universe.
A supernova occurs when a star emits a huge amount of energy at a very rapid rate, usually at the final stage of a collapsing star system. A supernova explosion is a spectacular and extremely luminous outburst of electromagnetic radiation.
Supernovae are similar to other explosions in that they release high-energy radiation in the form of gamma rays, x-rays, or protons. However, they have two distinct characteristics. One is that supernovae are the result of the implosion of a very large star at the end stages of its life. The other is that they tend to leave very little debris at the point of impact. Both these characteristics can tell astronomers a lot about what is happening in the vicinity of the explosion.
Astronomers know that supernovae occur in two different types.
One is Type Ia, which is the result of the collapse of a very massive star at the end stages of its life. Type IIa supernovae are thought to be the result of the merger of two very small stars. Whatever the case, it is clear from the types of supernovae that explosions involving Type Ia produce highly concentrated X-rays, gamma rays, and high-energy radio waves. These are the most frequently detected gamma rays in the universe, which makes them the tools for studying the properties of space and the universe in general.
When astronomers study supernovae, they come to recognize a variety of different phenomena.
First, there are the explosions that involve Type Ia supernovae. These can include gamma-ray bursts, matter swarms, and super vortex bursts. While it is not clear whether these events are produced by the same things or if they are unique to each type of supernovae, astronomers have a great deal of information to work with thanks to technology like gravitational lensing. Using the combined energy emitted from merging white holes and black holes, astronomers have been able to create a map of the entire sky that shows every X-ray point, including gamma ray bursts.
Astronomers have also been able to track supernovae by looking for changes in their light after their explosion. For instance, if a supernovae contained a nucleus of hydrogen, when it rapidly expanded, some of the hydrogen would escape into space. By taking images of these explosions with equipment called a Doppler instrument, astronomers have been able to identify the locations of these hydrogen escaping bubbles, which they can use to study the properties of the surrounding hydrogen gas.
The third type of supernova explosions occurs when a star explodes as it becomes very hot and expands rapidly.
This type has a name, referred to as a “white dwarf” because it consists almost entirely of hydrogen and helium, two of the most common elements in the universe. The core of this relatively cool target is extremely hot, with an average temperature of over a million degrees Celsius. When this core reaches a critical point, its outer shell collapses, creating a spectacular explosion of matter and radiation known as a thermal shock. The result is not too unlike a nuclear bomb, as nearly all of the energy in the explosion comes from hydrogen.
The last type of supernova explosions is known as a cosmic explosion, or a cosmic ray burst.
Unlike the other types, a cosmic explosion occurs as a result of a huge amount of energy being released with a bang. The blast happens when the universe reorients itself, spiraling inward in the process. It is possible to study the effects of cosmic rays through the use of instruments known as a gravitational lensing array, or a radio telescope.
When the outer shell of a compact white dwarf collapses, it leaves a ring of high-energy neutrons and helium in its center. This ring can reach a red giant’s size in only a few million years, which explains why scientists can see the supernova explosions by looking at a very faint red glow in the center of the explosion’s outer shell. When the ring becomes bright, it can be seen as a red giant, but it will also show up as a very bright source of infrared radiation called a reflected star. Scientists can determine the composition of the exploded object through analyzing the various colors that it gives off, but they also have to rely on data from radio telescopes like the orbiting Herschel Space Observatory and from ground-based telescopes like Gemini and Keck.