What is a dying star?

Hint: The number of galaxies in the observable Universe is estimated to be around 100 billion, hence there are around 100 billion stars born and dying per year, or about 275 million every day, in the entire observable Universe.

Complete answer:
1) Supernovae are colossal explosions that occur when certain types of stars die. When a star, such as the Sun, dies, its outer layers are ejected into space, leaving its hot, dense core to cool over aeons. A supernova can have the same brightness as a galaxy of billions of "regular" stars.

2) While most stars fade away peacefully, supergiants explode in a massive explosion known as a supernova. The creation of new stars can be triggered by the death of large stars.

3) The death of most stars takes millions of years. When a star, such as the Sun, burns through all of its hydrogen fuel, it grows into a red giant. The star falls after puffing off its outer layers, forming a compact white dwarf.

4) In a galactic the size of the Milky Way, a supernova occurs once every 50 years on average. To put it another way, a star explodes somewhere in the cosmos every second or so, and some of them aren't too far away from Earth. A star, on the other hand, can burn out in a blazing explosion if it has the correct amount of mass.

Note: Depending on their size, stars live for varying amounts of time. A star the size of our sun lives for around 10 billion years, whereas a star 20 times the mass of our sun lives for about 10 million years, or about a thousandth of that time. Stars are born from dense clouds of gas and dust.