what happens when the sun dies

The sun was created about 4.6 billion years ago. It is believed to exist for another 4.5-5.5 billion years. Astronomers believe that the life of the Sun will unfold according to the following scenario.

1. hydrogen burning stage. The sun produces four million tons of energy from 600 million tons of hydrogen in one second, and everything else turns into helium “ash”. The Sun is now believed to be 30% brighter than it once was. Experts suggest it will become 10% brighter in the next billion years. As a result, the temperature on Earth will rise, causing the ice to melt and the oceans to warm. In 3.5 billion years, when the Sun is 40% brighter, our planet will have no atmosphere, the glaciers will melt completely and the oceans will boil. As a result, the Earth will become dry and lifeless.

2. subgiant phase. In about five billion years, the Sun will consume all the hydrogen in its core. Also, the core will eventually shrink and condense, and its temperature will increase. As a result, this will lead to the ignition of hydrogen located outside the core. After that, the Sun itself will double and triple and turn into a supergiant star.

3. red giant phase. Gradually, the Sun will become a huge luminous object called a “red giant”. Such stars can be 100-1000 times the size of the current Sun. The temperature of the Sun’s surface will also drop to 3000°C. After that, the Sun will completely absorb Venus and Mercury and can reach Earth. However, there is a chance that our planet will not be completely destroyed, as the Sun will lose its mass during all this time (a maximum of 65-70% of the total mass will eventually remain). The core of the Sun will shrink and become hotter. And 12 billion years after the formation of the Sun, a new nuclear reaction will occur.

4. new red giant. The core of the Sun will begin to contract until its temperature reaches about 100 million °C. This will make it possible to ignite the helium, but it will not burn for very long – about 100 million years. As a result, the Sun will expand again.

5. planetary nebula. At this stage, the kernel will begin to shrink again. As the helium runs out, the Sun’s outer layers will be pushed out and lost into space. As a result, 12.5 billion years after the Sun’s formation, only half of its original mass will remain. The expanding outer layers will be illuminated by the core, creating a bright cosmic cloud – a planetary nebula.

6. white dwarf. After all the outer layers of the Sun have disappeared, only a hot dense core, called a white dwarf, will remain from it. Most of the heat will be trapped inside this object, and it will take tens to hundreds of billions of years to cool.

7. black dwarf. When the white dwarf has exhausted all its energy, it will turn into a lifeless black dwarf. Now scientists assume the existence of such objects, as the Universe is not yet old enough to create them.