What Is The Closest Star?

The Milky Way Galaxy is home to more than 100-billion stars that span a distance of over 100,000 light years. Thus, most of the stars in our galaxy are very far away from our solar system, yet some are practically in our cosmic backyard. The closest star to our solar system is Proxima Centauri, located a mere 4.2 light years away. If you were to travel at the speed of light, it would only take you 4.2 years to reach Proxima Centauri.

Characteristics Of Proxima Centauri 

Proxima Centauri
Hubble image of Proxima Centauri. Image credit: NASA/ESA

Proxima Centauri belongs to the Alpha Centauri star system, which is home to three individual stars. Each of these stars, including Proxima Centauri, are all red dwarf stars that are significantly smaller and dimmer than the sun. In fact, despite Proxima Centauri being only 4.2 light years away, it was only discovered in 1915 with the use of a telescope. Red dwarf stars are the most abundant type of star in the universe, yet not a single one is visible to the naked eye due to how dim they are. Proxima Centauri is only 12.5% the mass of the sun, 14% the size of the sun, and is only 0.0056% as bright as the sun. Despite it being so much smaller than the sun, Proxima Centauri will continue to shine for an estimated four trillion years, while the sun will burn out in around five billion years. Although red dwarf stars contain less hydrogen than other types of stars, they burn through it at a much slower rate, allowing them to exist for many trillions of years. 

Planets Of Proxima Centauri 

Proxima Centauri b
Rendition of the surface of Proxima Centauri b. Image credit: NASA/ESO

Not only is Proxima Centauri the closest star to us, it is also the closest solar system. As of 2022, astronomers have confirmed the existence of three planets around Proxima Centauri. The three planets are designated as Proxima Centauri b, c, and d. Proxima Centauri b is perhaps the most famous of the three and has garnered the most attention due to the fact that it orbits within the habitable zone of Proxima Centauri. Furthermore, Proxima Centauri b is only 1.07 times the mass of Earth and 1.3 times larger. Proxima Centauri b is one of the most Earth-like planets ever found in the habitable zone, and it is only 4.2 light years away.