Question

How fast will the sun become a red giant?

I've read many accounts of our sun's distant fate, but what I've never heard is on what time scale these events occur.

For instance, when the sun runs out of hydrogen, I presume it doesn't just WHAM! become a red giant suddenly, engulfing the inner planets in seconds. But how long would it take for the sun to expand? Would anyone left on Earth have days, weeks, months, years to escape? Centuries? What kind of time scales are we talking about, here?

Answer 1

The Sun will become a red giant over a long period of time, estimated to be about 5 billion years.

Step-by-step explanation:

The process of the Sun becoming a red giant is not sudden. It will happen over a long period of time. When the Sun runs out of hydrogen fuel, it will start to expand and become a red giant. This expansion will take place over millions of years. It is estimated that the Sun will become a red giant in about 5 billion years.