Why do stars stay stable?

Why do stars stay stable?

All stars are the result of a balance of forces: the force of gravity compresses atoms in interstellar gas until the fusion reactions begin. As long as the inward force of gravity and the outward force generated by the fusion reactions are equal, the star remains stable.

Why do all stars live long lives?

The length of a star’s life depends on how fast it uses up its nuclear fuel. Our sun, in many ways an average sort of star, has been around for nearly five billion years and has enough fuel to keep going for another five billion years. Almost all stars shine as a result of the nuclear fusion of hydrogen into helium.

Why do stars move across the sky?

This motion is due to the Earth’s rotation. As the spin of the Earth carries us eastward at almost one thousand miles per hour, we see stars rising in the East, passing overhead, and setting in the West. The Sun, Moon, and planets appear to move across the sky much like the stars.

Do the stars really move?

The stars are not fixed, but are constantly moving. The stars seem so fixed that ancient sky-gazers mentally connected the stars into figures (constellations) that we can still make out today. But in reality, the stars are constantly moving. They are just so far away that the naked eye cannot detect their movement.

How does the life cycle of a massive star differ from a low mass star?

On the right of the illustration is the life cycle of a massive star (10 times or more the size of our Sun). Like low-mass stars, high-mass stars are born in nebulae and evolve and live in the Main Sequence. However, their life cycles start to differ after the red giant phase. A massive star will undergo a supernova explosion.

What happens to a star at the end of its life?

The core is stabilized and the end is near. The star will now begin to shed its outer layers as a diffuse cloud called a planetary nebula. Eventually, only about 20% of the star�s initial mass remains and the star spends the rest of its days cooling and shrinking until it is only a few thousand miles in diameter.

When does a star become a main sequence star?

For most of its lifetime, a star is a main sequence star. It is stable, with balanced forces keeping it the same size all the time. During this period: The Sun is expected to be a main sequence star for billions of years.

What happens to stars that are more massive than the Sun?

Stars that are much more massive than the Sun continue the fusion process until they reach a point where the core collapses. The outer layers also collapse onto the core and then rebound out to space in a catastrophic explosion called a supernova.