0
These values are very approximate and work on the principal of life meaning something akin to life on Earth.
The more we get to know about "silicon" creatures or hydrogen floating "species" then this can be thrown out of the proverbial window.
It is only a very simplistic view of what *could* be.
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There are about 100 billion galaxies in the Universe.
On average, say, each galaxy contains 100 billion stars.
That's a total of 10,000,000,000,000,000,000,000 stars.
Now astronomers believe that 50% of all stars are part of a binary (or more) system and because of the orbit of the binary pair, the existence of any life, close to a rotating binary pair is slim - but not impossible. However, for simplicity, lets remove 50% of the stars. We are now left with 5,000,000,000,000,000,000,000 stars.
Now, life has to exist around a star that is "burning", so a red giant or a red dwarf are not likely candidates for extrasolar life. It's not impossible, but lets keep it simple. 80% of all stars are in this category, so reject them and we are left with 1,000,000,000,000,000,000,000 stars.
For intelligent life to evolve, we need time, so we need a star that will last a long time. Hot bright stars, are very hot and burn out way too quickly. So let's reduce them - about 5%, so 950,000,000,000,000,000,000.
This is an approximate number of class F, G and K stars - ours is a G star. Those that are not part of a binary or more star system.
So this equates to about 9,500,000,000 possible stars per galaxy that are of the "right" type.
Now the Earth is pretty special - we know this. It has to be right distance from Earth (The Goldilocks zone). It has to be a certain mass to "hold" onto an atmosphere, and it needs a molten core to produce a Van Allan belt to protect life from solar radiation.
So let's say there is a one in a billion chance of all these things happening around one of "our" stars. This means that there is only a "best" chance of 9 1/2 stars in a galaxy having the "right stuff".
Oh dear - not very good - especially as the Milky Way - our Galaxy has upwards of 200 billion stars, Only nine of them are possible areas for life!!!!
So let's change that to a one in a million chance.
That gives us a chance of 9,500 possible stars in a galaxy.
Much better.
*NOTE* This is all a very rough approximation.
What else can I help you with?
What do all the planets orbit around?
All the planets in OUR solar system orbit around the sun(which is a star). Planets in other solar systems orbit around other stars.
Are there any planets out of our solar system that orbit around stars?
Yes. As of August 2015 scientists have discovered nearly 2,000 planets orbiting other stars.
how many planets have been discovered around stars other than sun?
42.068
Do planets form around stars?
Yes, planets form around stars. In order to be a planet, one of the requirements is that you have to orbit around a sun. Also, as far as physicists can tell, planets form in the dust of other stars that have already died and left their matter.
What is the sun and all the planets around it called?
It is called the solar system. There are also systems around other stars.
What planets are out there that's are not in your solar system?
These are planets that are in orbit around other stars, known as exosolar planets.
What do all the planets orbit around?
All the planets in OUR solar system orbit around the sun(which is a star). Planets in other solar systems orbit around other stars.
Do the stars orbit the planets or do planets orbit stars?
Moons orbit planets. Planets orbit stars. Some stars orbit other stars, or orbit their mutual center of gravity. Stars orbit the center of the galaxy. Galaxies may orbit the center of the "galactic group".
What are star planets called?
That doesn't make sense. There are stars, and there are planets. If you mean "planets around stars, other than the Sun", those are usually called "extrasolar planets" or "exoplanets".
Do any of the stars you can see have planets around them?
Yes. To date scientists have discovered well over a thousand planets orbiting other stars. It is believe that a large portion of the stars in the night sky have planets.
Is our sun the only star that has planets orbiting around it?
No. Other stars have been found to have planets orbiting them.
Is stars planets?
No. Stars are like suns, around which planets may orbit.
Can planets and stars orbit around the sun?
Planets orbit the sun. Stars do not.
What is a group of stars and the planets and other objects orbiting around it?
Solar system
Could other stars have a solar system?
Absolutely. We are finding more and more planets [Exoplanets] around other stars everyday.
Are there any planets out of our solar system that orbit around stars?
Yes. As of August 2015 scientists have discovered nearly 2,000 planets orbiting other stars.
Do planets and moons have stars?
On the contrary! A star has planets, which circulate it. And planets have moons. Stars do not circle planets.
