Stars — do they really twinkle?

Twinkle, twinkle, little star… We have all heard or sang this song as a kid. But is the

song actually based on facts? Do stars really twinkle or is it just an illusion?

Credit: Vadim Sadovski/Shutterstock.com

What are stars?

According to the Cambridge English Dictionary, a star is “a very large ball of burning gas

in space that is usually seen from the earth as a point of light in the sky at night”. Stars

are just huge celestial bodies of helium and hydrogen that emits light and heat due to

the movement of their nucleus. Stars contain plasma inside them that is held together

due to gravity. NASA estimates that there are over 100 billion stars in our galaxy alone!

P.S: the galaxy where Earth is located is called The Milky Way Galaxy.

Credit: EduRev

Do stars really twinkle?

For you to really understand the answer to this question, you need to know why stars

shine in the first place…

Stars shine due to the fact that an immense amount of pressure caused by gravity is

holding them together. This pressure causes the nucleus (or the core) of the star to heat

up and start the process of nuclear fusion. Nuclear fusion is the process of combining

two atomic nuclei and forming a single and bigger one. When this process happens

inside a star, it combines hydrogen atoms and usually forms a bigger helium one. This

causes the core of the star to generate energy, creating heat in the core and causing it

to glow. Just like a campfire, the hotter the stars get, the stronger they will shine!

Now raises the question “do stars really twinkle?” Well, let’s find out…

In short, stars actually don’t twinkle. The twinkling that we see is merely an illusion.

Stars appear to twinkle because as light enters the earth’s atmosphere the light is bent

and distorted due to winds, temperature, and density of the air. This effect is only seen

from earth. For example, if we go up close to the stars they in fact don’t twinkle, they

just glow.

Why do some stars glow in different colors?

Stars are classified by a number of different factors. The glow of a star can vary due to

temperature and distance from earth… For example, the closer a star is to earth, the

brighter it will appear to us. And the farther a star is, the dimmer we will see it.

Sometimes we see stars that appear to shine in colors… This is due to the temperature

of a star. The coldest stars usually have a red-brown color. Hot stars, on the other hand,

shine in blue color. Our sun is in the middle-temperature zone, not the hottest; but not

the coldest. Hence, it shines in a yellow to white color.

The next time you look up in the sky and find a twinkling star, remember why they seem to

twinkle and the wonders that stars possess.

References:

1-https://www.nationalgeographic.com/science/article/stars

2-https://www.coolkidfacts.com/how-do-stars-shine/

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