Why does a star dim and cool as it ages?
Star
Why does a star dim and cool as it ages?
Imagine a star as a glowing light bulb. Over time, the bulb starts to flicker and dim, even though it still looks bright from a distance.
A star's core runs out of fuel, causing it to expand and cool down. This process makes the star's surface less bright and cooler, much like a light bulb that dims when it runs low on power.
Example
The Sun, our star, will eventually burn out its fuel and become a red giant, glowing less brightly and cooler than it does now.
Remember this
A star dims and cools as it ages because it exhausts its nuclear fuel, leading to expansion and a cooler surface temperature.
Text adapted from Wikipedia, licensed under CC BY-SA 4.0.
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