The Nearest Neighbor Star

You might expect the nearest star to Earth to be one that’s very easy to spot.

However, if you want to find the small and dim Proxima Centauri, you’d have to look a little closer.

The Nearest Neighbor Star

Not only is it too dark to spot with the naked eye, it’s outshined by the nearby Alpha Centauri system.

Our nearest neighbors can teach us a lot about our own solar system, as well as the universe as a whole.

Take a look at this guide to find out what we know about our closest neighbors, as well as all the things we’ve yet to discover.

What Is The Next Nearest Star To Earth?

Of course, the very nearest star to Earth is our sun! The sun is roughly 93 million miles away from Earth.

Our next nearest star is significantly further away.

The next nearest star to Earth is Proxima Centauri. However, it isn’t alone.

Proxima Centauri is part of the Alpha Centauri star system, which also contains Alpha Centauri A and Alpha Centauri B.

The Alpha Centauri system was once thought to be just a single bright star, as it appears this way to the naked eye.

It was recognized as a binary star, a system of two stars gravitationally bound together, in 1689. Proxima Centauri wasn’t discovered until 1915.

Proxima Centauri

Proxima Centauri is the closest star to Earth not in our solar system.

Although it appears quite bright through the Hubble telescope, it’s not visible to the naked eye.

Because of this, Proxima Centauri wasn’t discovered until 1915.

Proxima Centauri is a red dwarf star. It has a mass roughly 12.5% the mass of the sun, but around 33 times the density.

It’s also a flare star, which means it can seem at times brighter, with extreme flares caused by magnetic activity.

Proxima Centauri completes a rotation once about every 83 days.

It’s thought that Proxima Centauri is a companion to the binary stars Alpha Centauri A and B.

Because of this, it’s sometimes known as Alpha Centauri C.

Alpha Centauri A And B

Alpha Centauri A And B

Proxima Centauri may be closer, but Alpha Centauri A and B were identified several centuries in advance.

These binary stars are sun-like, and are the brightest stars in the Centaurus constellation.

Viewed as the binary star Alpha Centauri AB, this is the third-brightest star in the night sky.

Alpha Centauri A is the bigger of the two stars, larger and brighter than the sun. Alpha Centauri B is cooler and smaller.

Alpha Centauri A is the nearest sun-like star to Earth. Both stars orbit a common center, with an orbital period of 79 years.

Although Alpha Centauri A and B aren’t currently the nearest stars to Earth, they will be eventually.

In about 25,000 years, Alpha Centauri A and B will move closer and alternate the title nearest neighbor every 79 years or so.

How Far Is The Nearest Neighbor Star?

The Alpha Centauri star system is 4.37 light-years from the Sun. A light-year is a unit of length used to measure large astronomical distances.

One light-year is equal to about 5.88 trillion miles. So, Alpha Centauri is around 26 trillion miles away from us.

Proxima Centauri, however, is slightly closer. The Earth’s nearest neighbor star, Proxima Centauri is only 4.264 light-years away.

Alpha Centauri A and B are about 23 astronomical units (AU) from each other, which is about the distance between the Sun and Uranus (or 23 times the distance between Earth and the Sun).

This is the average distance. As the stars orbit each other, the closest they come together is a distance of 11 astronomical units.

Proxima Centauri is significantly further away, which has led to some wondering if the system is actually linked, or if Proxima Centauri is just a visitor.

Proxima Centauri is about 13,000 astronomical units away from Alpha Centauri AB.

How Long Would It Take To Get To The Nearest Neighbor Star?

If we ever choose to visit another star, the first choice would be our neighbor, Proxima Centauri. However, don’t expect a quick visit.

At a distance of 4.264 light-years from the Sun, it’s likely to take tens of thousands of years to travel.

The Voyager 1 probe left earth in 1977 and is now in interstellar space.

Traveling at a rate of 38,210 miles per hour, a Voyager-like spacecraft would take 73,000 years to reach Proxima Centauri.

The New Horizons probe set off at a slightly quicker speed of 52,000 mph.

Even at this incredible speed, it would take 54,400 years to reach Proxima Centauri.

NASA’s Juno probe travels at roughly 165,000 mph, and wouldn’t reach Proxima Centauri until 17,160 years in the future.

No matter how quick the robotic probes are, a journey to Proxima Centauri will never be a short trip.

Even traveling at the speed of light, a trip to Proxima Centauri would take just over 4 years.

So, a journey to our nearest stellar neighbor is a long way off.

Despite the distance, this star is still considered a good candidate for future exploration!

Does Our Closest Neighbor Star Have Any Planets?

Does Our Closest Neighbor Star Have Any Planets

Finding planets at distances such as this is difficult, but it’s thought that there are at least 2, possibly 3, planets orbiting Proxima Centauri.

These are known as Proxima Centauri b, Proxima Centauri c, and Proxima Centauri d.

Proxima Centauri b orbits close to the star and is thought to be an Earth-like planet with a similar mass to us.

Because it’s so close to the star, it’s theorized that Proxima Centauri b is tidal locked — always facing one direction.

Proxima Centauri c is further away and larger. It’s estimated to have a diameter of about 7.5 Earths.

Proxima Centauri c is thought to have a ring system.

Proxima Centauri d is thought to be significantly smaller than Earth, and orbiting very close to its star.

Could These Planets Support Life Forms?

If you’re excited by the hunt for life on other planets, you might want to start looking on Proxima Centauri b.

It orbits in the habitable zone of Proxima Centauri, meaning that there could be liquid water on the surface, and maybe signs of life.

But because Proxima Centauri has occasional solar flares, the atmosphere on the planet would be very different to ours.

And one massive flare has the potential to wipe out life entirely.

It’s very hard to know any details about the roughly Earth-size Proxima b.

It’s so much smaller than its star, and so far away, that observation is supremely difficult.

However, because it’s in that habitable zone, and due to the long lifespan of red dwarf stars, life could potentially develop.

What Other Stars Are Close To Earth?

The Alpha Centauri system contains the nearest stars to our Sun, at a distance of 4.37 light-years away.

Our next closest companion is Barnard’s Star. This is a red dwarf star found roughly 6 light-years from our Sun.

It can’t be seen by the naked eye and is considerably older than the Sun.

From there, the next nearest neighbors are the brown dwarf stars Luhman 16 and WISE 0855-0714.

Look a little further, and Wolf 358 is roughly 7.9 light-years from Earth.

Final Thoughts

Our nearest neighboring star, Proxima Centauri, is not exactly close to our Sun.

In fact, if you want to visit, expect a journey lasting tens of thousands of years. But it’s certain to be worth the trip.

Proxima Centauri b might be an important step in the search for life in space.

Gordon Watts