What is a supernova? From supernovas, what have scientists learned? How are supernovas studied by scientists?
What is a supernova?
A supernova is a powerful explosion that occurs when a star runs out of fuel and collapses under its own gravity. The blast is so powerful that it can briefly outshine an entire galaxy.
Supernovas are very bright. These spectacular events can be so bright that they can outshine entire galaxies for days or even months. They can be viewed all around the universe.
One type of supernova, called a “core-collapse” supernova, occurs in the last stage of the life of massive stars that are at least eight times larger than our Sun.
Supernovas are not very common. According to astronomers, galaxies like our own Milky Way experience two to three supernova explosions every century.
Because there are so many galaxies in the universe, scientists see a few hundred supernovas per year outside our galaxy.
From Supernovas, what have scientists learned?
By studying supernovas, scientists have discovered a lot about the universe. They use the second type of supernova—the one that involves white dwarfs—as a ruler to measure the distances in space.
In addition, they now understand that stars act as the universe's factories. Stars generate the chemical elements required to create everything in our universe.
Simple elements like hydrogen are converted into heavier elements at the cores of stars. These heavier elements, like carbon and nitrogen, are essential elements for life to exist.
Gold, silver, and uranium are heavy elements that can only be made by massive stars. Supernova explosions distribute both stored-up and newly-created elements throughout space.
How are Supernova studied by scientists?
In order to search for and study supernovae, NASA astronomers use a number of different types of telescopes. One example is the NuSTAR mission, which studies the cosmos using X-ray vision.
To better understand what occurs before, during, and after these magnificent explosions, scientists are observing supernovas and young nebulas with the help of NuSTAR.