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How many Stars are there in the Universe and the Milky Way?


Published on: February 1, 2022,

If you look up at the sky on clear night you will see thousands of stars. You might count around 6,000 or so. That’s only fractions of the stars. The rest are too far and are invisible.


Galaxies are diverse. Like people they come in different shapes and sizes. Earth is in Milky Way. It’s a spiral galaxy. Its stars cluster in spiral arms that swirl around galaxies center.  Other galaxies are elliptical and some are irregular with variety of shapes.


Before counting the number of stars astronomers has to estimate number of galaxies. To do that they take very detailed pictures of small parts of the sky and count all the galaxies they see in those pictures. There are 2,000,000,000,000 galaxies in the universe – that’s 2 trillion.


Counting the stars


But astronomers do not know exactly how many stars are in each of those 2 trillion galaxies. But we can guess at the number of stars in our Milky way. Our sun is a white star . Bigger, heavier and hotter stars tend to be blue like Vega in the constellation Lyra. Smaller, lighter and hotter stars are usually red like Proxima Centauri.


An incredible number


Red, white and blue stars give off different amounts of light. By measuring that starlight – specifically its color and brightness. Astronomers can estimate how many stars our galaxy holds.  With that method Milky Way has about 100 billion stars.


Next we will make Milky Way as our model. We can multiply the numbers the number s stars in typical galaxy (100 billion), by the number of galaxies in the universe ( 2 trillion).


The answer is an absolutely astounding number. There are approximately 200 billion trillion stars in the universe. That’s  200,000,000,000,000,000,000,000! It’s about 10 times the number of cups of water in all the oceans of Earth.


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