how many stars are there in the universe?

Answer 1

Ok, how about this:

Astronomers estimate that there are at least 70 sextillion (7×10^22) stars in the known universe. That is 230 billion times as many as the 300 billion in our own Milky Way.

(shamelessly stolen from Wikepedia)

Answer 2

This question is very important because it will bear on the weight of our universe which will determine whether the universe's expansion will ultimately halt and the universe fall back into itself.

There are roughly 20 million visible galaxies. However, not all galaxies are equal. They come in different shapes, sizes and masses. So a back-of-the-enveloppe calculation would average this to 10 million spirals & ellipticals containing on average 200 billion stars, and the rest would be dwarf galaxies with <100 million stars. This adds up to about 4 billion-billion stars (visible).

Of course this is a lower limit since these is visible data.

A better estimate would use the distribution of galaxy type and mass as well as an age (evolutionary) effect because younger gals may have more gas that will be turned into stars, etc.

doctor P
http://spacegeek.org
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Answer 3

First of all the observable universe is not infinite but is calculated as having a diameter of 156 billion light years. There may or may not be anything beyond what we can observe, but by definition, we will never know that, will we? It may be finlte or it may be infinite, but we will never know that, either. We have no way of telling.

Astronomers from the Australian National University have come up with a best guestimate of 70 sextillion (7 x 10^22) stars in the observable universe. They did this by studying star densities in sample spaces and then working out how many such spaces there are in the observable universe.

Here is an edited version of one article reporting this:

"70 sextillion stars in the 'known' universe!

According to a study by Australian astronomers there are 70 sextillion (70,000,000,000,000,000,000,00... stars in the known universe.

It's also about 10 times as many stars as grains of sand on all the world's beaches and deserts.

The figure was calculated by a team of stargazers based at the Australian National University.

Speaking at the General Assembly of the International Astronomical Union meeting in Sydney, Dr Simon Driver said the number was drawn up based on a survey of one strip of sky, rather than trying to count every individual star.

The team used two of the world's most powerful telescopes, one at the Anglo-Australian Observatory in northern New South Wales state and one in the Canary Islands, to carry out their survey.

Within the strip of sky some 10,000 galaxies were pinpointed and detailed measurements of their brightness taken to calculate how many stars they contained.

That number was then multiplied by the number of similar sized strips needed to cover the entire sky, Driver said, and then multiplied again out to the edge of the visible universe.

He said there were likely many million more stars in the universe but the 70 sextillion figure was the number visible within range of modern telescopes."

(shamelessly stolen from Wikipedia, the modern oracle)

Answer 4

There are thought to be 200 billion stars in our Milky Way Galaxy and our galaxy is the average galaxy, and there are thought to be 200 billion galaxies in the Universe to therefore there are about 40 trillion stars in our Universe.

Answer 5

Three years ago a research group determined that the total number of stars in the OBSERVABLE universe is about 70-sextillion. This number is only for that part of the universe we can ever observe--the total universe is considerably larger.

Answer 6

I really dont know if anyone has counted them one by one. If you were to count one by one there would not be enough life times to do so.
Stars were estimated by how dense the galaxy that contains them.
It was calculated to be about one trillion Galaxies in This Universe.
So if we estimate the Number of stars in the milky way and multiply that by 10^12 you would have a very rough aproximation.
I assume you really did not expect us to give you an exact number. On the other hand I can say there are enough stars.

Answer 7

There is 150 billion stars in our galaxy but there is more galaxies then stars in our milky way.Count that and maybe you will get answer

Answer 8

A complete survey of the universe has not been done. Billions and billions have been mapped.

Answer 9

Incalculable.
We are still finding them close by.
It has been said that moving, they are impossible to count and that's just the stars that we can see.

Answer 10

there are more stars in the universe than there are grains of sand in all the beaches and deserts on our planet