How Many Suns Are There In A Universe?

Our solar system is just one specific planetary system—a star with planets orbiting around it. Our planetary system is the only one officially called “solar system,” but astronomers have discovered more than 3,500 other stars with planets orbiting them in our galaxy. That’s just how many we’ve found so far. There are likely to be many more planetary systems out there waiting to be discovered!

Our Sun is just one of about 200 billion stars in our galaxy. That gives scientists plenty of places to hunt for exoplanets or planets outside our solar system. But our capabilities have only recently progressed to the point where astronomers can actually find such planets.

The Sun Explained

Our Sun is a star comprised primarily of hydrogen that it fuses into helium atoms. This process, known as nuclear fusion, emits both the heat and light that make their way to the Earth (and beyond). The Sun is massive compared to our planet, but it is actually quite average next to other stars.

There’s nothing about the Sun that really makes it stand out. It is a yellow dwarf star that averages a temperature of 5,700 Kelvin on its surface. This is nothing compared to stars that can reach in excess of 50,000 K.

It is also not particularly bright or large in diameter or mass. The largest star in the known universe, UY Scuti, has a diameter roughly 1,500 times our star. UY Scuti is also ten times more massive and glows 340,000 times brighter. Can you imagine if we had ended up with UY Scuti instead of our Sun?

While the Sun isn’t all that special in the grand scheme of things, it is our star. It’s a perfect size and has enough heat and light output to keep us alive.

Why is it hard to find planets outside our solar system?

Even our closest neighboring stars are trillions of miles away. And all stars are enormous and extremely bright compared to any planets circling them. That means that picking out a planet near a distant star is like spotting a firefly right next to a brilliant lighthouse miles away.

What is it like in other planetary systems?

So far, the planets outside our solar system have proven to be fascinating and diverse. One planet, known as HD 40307g, is a “super Earth,” with a mass about eight times that of Earth. The force of gravity there would be much stronger than here at home. You would weigh twice as much there as you do on Earth!

Another planet, called Kepler-16b, turns out to orbit two stars. A sunset there would provide a view of two setting stars!

In another planetary system, called TRAPPIST-1, there are not one…not two…but seven Earth-sized planets that could be covered in liquid water. The planets are relatively close together, too. If you were to stand on the surface of a TRAPPIST-1 planet, you might see six other planets on the horizon!

How Many “Suns” Are in The Milky Way?

Of the research conducted on our Milky Way galaxy so far, scientists have located just over 3,500 stars with planets circling around them. Each of these orbiting bodies is called “exoplanets,” which simply means they represent a planet that orbits a star outside our Solar System.

Interestingly, Proxima Centauri is the nearest star to our Sun and has two confirmed exoplanets. One of these two worlds may exist within the star’s hospitable zone and could even have an ocean of liquid water. Being a red dwarf star, Proxima Centauri has some flare activity that could have damaged the exoplanet’s atmosphere or the amount of water it has.

Even if this world is deemed suitable for human life with water and breathable air, it still begs the question of how to get there. Traveling at the speed of light, it would still take 4.2 years to make the trip.

Kepler-47 is a binary star system with three confirmed exoplanets orbiting the two stars. One star has 85% of the output of our Sun, while the other only provides 1% of the Sun’s light. This system has at least one star in its hospitable zone but exists over 3,000 light-years from us.

Although we’ve only scratched the surface of what’s out there, it’s estimated that there could be upwards of 6 billion Earth-like planets in the Milky Way. Add that to gas planets and other sized worlds, and there could easily be 100 billion exoplanets in our galaxy alone.

How will astronomers keep finding distant solar systems?

NASA’s Kepler mission found more than 2,600 exoplanets during its nine-year mission. It has also made a list of more than 3,000 additional potential exoplanets that astronomers need to study more carefully to be sure that they are indeed planets.

NASA’s Transiting Exoplanet Survey Satellite (TESS) mission is continuing the hunt for exoplanets. While Kepler primarily searched within one particular patch of the sky, TESS is observing the entire sky to locate thousands of planets orbiting the nearest and brightest stars.

The James Webb Space Telescope, set to launch in 2021, will also observe many of the exoplanets we have discovered and help scientists reveal details about these distant worlds.

Who knows? One day, by studying exoplanets and distant solar systems, astronomers hope to answer the intriguing question: Is there life elsewhere in our galaxy?


Is there only 1 Sun?

The sun is the star at the center of the solar system. It is the biggest and most important star in our galaxy. Our galaxy the Milky Way contains about 200 billion stars. It is estimated that there are about 100 billion galaxies in the observable universe. So, it is very likely that there are many more suns in the universe!

How many suns are there in this universe?

There are an estimated 100 billion stars in our Milky Way galaxy alone making up about 100 billion suns. So, there are likely billions of other galaxies with billions of suns. There is no definite answer but it is thought that the number of suns in the universe is vastly larger than any human could ever conceive.

How Many Solar Systems Are in Our Galaxy?

So far, astronomers have found more than 500 solar systems and are discovering new ones every year. Given how many they have found in our own neighborhood of the Milky Way galaxy, scientists estimate that there may be tens of billions of solar systems in our galaxy, perhaps even as many as 100 billion.

Will there be 2 suns?

There is no way to know for sure but it is likely that there will be two suns in the universe. This is because the universe is expanding and the two Suns will eventually drift apart.

Can a planet have 3 suns?

A planet can have three suns if the planet has three orbits around a central star. Although we may never know the precise number of suns in the universe, we can be sure that there are many more than we could have ever imagined.