# How many stars?

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How many stars are there in the sky? How do u get to this number ?

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There are 200 billion trillion stars in the universe. To find total number of stars astronomers first calculate the number of galaxies by taking the highly detailed pictures of tiny parts of sky and then count all the galaxies that are visible in those pictures. The number of galaxies found by those pictures is multiplied by the number of pictures needed to photograph the entire sky. To this date astronomers have found about 2 trillion galaxies in the universe. The they measure the total number of stars in each galaxy by estimating the starlight of each star which tells us about its color and brightness. Astronomers have found about 1 billion stars in milky way by measuring their starlight. Now, we get the total number of stars in universe by multiplying the number of stars in a galaxy(milky way) to the total number in the universe. If we multiply 1 billion stars to 200 trillion galaxies, we get 200 billion trillion galaxies in the universe.
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There is no definitive answer to this question because the number of stars in the sky varies depending on the time of day, location and visibility. Generally, it is estimated that there are about 100–200 billion stars in the Milky Way galaxy, with 100–400 billion galaxies in the observable universe.

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The number of stars in the universe is estimated to be around 10^22 (10 sextillion or 10 billion trillion). However, this number is constantly changing as new stars are formed and old stars die. Additionally, the number of stars that can be observed from Earth is limited by our technology and the distance to the stars.
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There are an estimated 100 billion stars in the Milky Way galaxy alone, and there are an estimated 2 trillion galaxies in the observable universe. This means that there are potentially around 200 sextillion (200,000,000,000,000,000,000) stars in the observable universe.

Keep in mind that these are estimates and the actual number of stars in the universe may be much higher, as it is difficult to count the exact number of stars, due to the vastness of the universe and the limitations of current technology.

Scientists use a number of methods to estimate the number of stars in the universe. One method is called "star counts," in which scientists observe a small patch of the sky and count the number of stars within that patch. They then use that data to estimate the total number of stars in the entire sky. Another method is called "luminosity function," in which scientists use data on the brightness of stars to estimate the total number of stars in the universe.

Another method is called "Extragalactic background light (EBL)" which measures the total amount of light emitted by all the galaxies in the universe, and then assuming that each galaxy has an average number of stars, the total number of stars can be estimated.

It's also important to note that these estimations are based on current technology and knowledge, and as technology and understanding of the universe improves, these numbers may change.
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200 billion trillion stars exist. Astronomers count all visible galaxies in extremely detailed photographs of small regions of the sky to compute the total number of stars. The amount of photographs required to photograph the sky multiplies the number of galaxies detected. Astronomers have discovered 2 trillion galaxies. They estimate each star's starlight to count its stars in each galaxy. Astronomers measured illumination from 1 billion milky way stars. Multiplying the number of stars in a galaxy (Milky Way) by the total number in the universe gives us the total number of stars. 200 billion trillion galaxies result from multiplying 1 billion stars by 200 trillion galaxies.
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It is estimated that there are between 100 billion and 400 billion stars in the Milky Way galaxy. This number is based on observations of the number of stars in other galaxies and extrapolations of their sizes.