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What Is the Closest Star to Earth? The Interesting Answer!

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the earth with a far away star

The scientific revolution in the 60s Space Race left people wondering about the closest star to the Earth.1 The closest star to Earth is the Sun, and the next closest star is an entire star system called Alpha Centauri. The sun is about 150 million kilometers away from Earth, or about 8.5 light-minutes.

Alpha Centauri or Rigil Kentaurus is a triple-star system with Proxima Centauri as the primary star. It is the closest star to the Earth other than the Sun, located about 4.3 light-years away from Earth.

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The Alpha Centauri System

The Alpha Centauri System is one of the rarest cosmic systems, constituting 10% of the total systems with similar traits. The first two stars of this triple-star system are Alpha Centauri A and Alpha Centauri B.

These stars are situated at a distance of 23 astronomical units from each other. The third star, Proxima Centauri, is approximately 600 times away from its siblings. Compared to the Earth, this distance equals almost 4.3 light-years away.

Alpha Centauri A is the brightest star that resembles the Sun in multiple aspects, including diameter, absolute magnitude, and spectral type. Meanwhile, the second brightest star, Alpha Centauri B, is relatively redder than Alpha Centauri A. The third and the last star, Proxima, falls under the red dwarf stars category.

From Earth, the Alpha Centauri system is the fourth brightest, after Sirius (the brightest), Canopus, and Arcturus. Although you can see all these stars with a naked eye, Proxima won’t be very visible.

Does Alpha Centauri Have Habitable Planets?

Suppose humans make their way to the Alpha Centauri system. But what good would all these efforts bring if people can’t live there? This leads to another question that many astronomy lovers ask: Does Alpha Centauri have any habitable planets?

Astronomers aren’t very confident about answering this question, but it could be possible. In fact, some astronomers discovered an exoplanet in 2016 with a diameter of 1.3 times more than the Earth. Later, it was named Proxima b and became famous as the closest planet to the Earth for colonization.

Proxima b has an 11.2-day orbital period, putting it within the habitable zone of Proxima. In addition, it is located where liquid water exists on a planet’s surface. This indicates that Proxima b can support life. However, scientists are still skeptical whether the planet can provide life like the Earth. Because of insufficient research and data, some astronomers have different theories.

For instance, since Proxima b is near Proxima Centauri, its one side encounters celestial objects. This could turn one side of the planet into a burning hot place and the other a frozen, cold desert.

Another factor is that Proxima Centauri is a red dwarf emitting lethal radiation in their systems. So, this could affect the possibility of the existence of life.

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What Are the Other Closest Stars to Earth?

Our Milky Way galaxy consists of more than 100 billion stars. Luckily, many of them are in the Earth’s atmosphere, which we can see from our naked eyes.

Here is a list of the nine nearest stars to the Earth besides Proxima Centauri:

The Sun

The Sun doesn’t need any introduction. It is a huge star included in the yellow dwarf category. Moreover, the Sun is one of the oldest parts of our solar system that has been around for more than 5 billion years.

The Sun makes the Earth bright in the daytime and the Moon at night. It is just 8.5 light-minutes away from the Earth, translating to almost 150 million kilometers.

the sun in the solar system

Image Credit: Lukasz Pawel Szczepanski, Shutterstock

Barnard’s Star

Named after a US-based astronomer, E.E. Barnard, Barnard’s star lies in the faint red dwarf category. It is the next closest star to the Earth, with a distance of about 5.95 light-years.

The exciting thing about Barnard’s star is that astronomers suspected it had planets back in the day. They even tried to discover these planets but failed every time.

Wolf 359

If you’re a Star Trek fan, you may have already recognized this star. Wolf 359 has a distance of only 7.78 light-years from the Earth. Unfortunately, it’s not bright enough to be seen with the naked eye. Like Barnard’s star, Wolf 359 is a faint red dwarf star near the constellation Leo.

Lalande 21185

Lalande 21185 is another faint red dwarf present in the Ursa Major constellation. It is named after a French astronomer, Joseph Jérôme Lefrançois de Lalande, in the 19th century. Like the other stars in this list, Lalande 21185 is too dim to be noticed by the naked eye.

This star is 8.39 light-years away from the Earth, so it’s almost impossible to travel there.

Sirius

Sirius is the brightest star in the night sky. Since ancient times, many civilizations have considered the star an indicator of season change. Even Egyptians used Sirius as a harbinger of planting.

Sirius is a two-star system consisting of Sirius A and Sirius B. It lies 8.58 light-years away from the Earth in the Canis Major constellation. Sirius B comes under the white dwarf stars category, which will be the remains when the Sun reaches its life’s end.

Sirius star the brightest star seen from Earth

Image Credit: Billion Photos, Shutterstock

Luyten 726-8

Luyten 726-8 is also a two-star system in the Cetus constellation. It is named after Willem Jacob Luyten. You may also know it as Gliese 65. The system is 8.73 light-years away from the Earth.

Ross 154

Astronomers call Ross 154 an active flare star, named after US-based astronomer Frank Elmore Ross in 1925. It falls under the red dwarf category and is located 9.68 light-years away from the Earth.

Ross 154 enhances its surface brightness within a few minutes and then dims down instantly for some time. This star lies in the Sagittarius constellation, very close to Barnard’s star.

Ross 248

Ross 248 is almost 10.3 light-years away from the Earth, lying in the Andromeda constellation. Nevertheless, it is moving so quickly through space that scientists believe it can even take over the Sun and Proxima Centauri to be the closest star to Earth in about 36,000 years. Like its sibling, Ross 248 is also a dim red dwarf star.

Epsilon Eridani

Epsilon Eridani is the third most visible star to the naked eye. It is 10.52 light-years away from the Earth, lying in the Eridanus constellation.

Epsilon Eridani has multiple planets orbiting around it, making it a unique star. It is surrounded by a dust disk that looks like a planet. Some of these objects may be present in the habitable zone where liquid water exists on the planet’s surface.

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Conclusion

There you have it! Many scientists believe the Alpha Centauri system is the nearest star system to the Earth, though our sun is the closest star to our planet. Alpha Centauri may also have habitable planets with visible signs of liquid water.

The other closest stars to the Earth are Barnard’s star, Wolf 359, Lalande 21185, Sirius, Luyten 726-8, Ross 154, Ross 248, and Epsilon Eridani. Go forth and use this newly found knowledge to impress your friends!


Featured Image Credit: GooKingSword, Pixabay

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.

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