A supernova is a huge explosion at the end of the life cycle of a star. They are quite rare, but when they do occur, they can outshine whole galaxies.
A supernova is huge explosion that occurs at the end of the life cycle of a star. They are quite rare, but can be huge events radiating more light than our Sun will radiate in its lifetime. The term 'supernova' comes from the Latin for new (nova) and above (super), as supernova appear to be new stars in the night sky. The term was first coined by Walter Baade and Fritz Zwicky in 1931.
There are two ways a supernova can occur. The first happens in a binary star system. A binary star system is one of two stars that orbit around a central point. In this system, one star can accumulate material from the other star, increasing its own mass. When the star reaches a certain mass, the star can explode. After the explosion has occurred, what remains of the star is an extremely dense core, known as a neutron star. If the star is extremely massive, black holes can form.
It is difficult to observe supernova in our own galaxy as they are often obscured by dust. The last supernova observed from within our galaxy was by Johannes Kepler in 1604. It was observable with the naked eye and could even be seen during the day for nearly a month.
The first recorded supernova observed was in 185 BCE by Chinese astronomers. Records indicate it was observable from Earth for eight months. There have been three supernova explosions that have occurred within our own galaxy during the last 1000 years which you able to be seen with a telescope.
Supernovae are important as they distribute elements heavier than iron throughout the galaxy. Supernovae are also important as a tool for scientists to measure distances in the universe. Type 1a supernova are known as standard candles because they all emit a similar type of light when they occur. Scientists can compare these supernovae and measure how far away they are.