Alpha Centauri: the closest stars to Earth, and can you see them?

After the Sun, the closest star to Earth is Proxima Centauri, about 4.25 light-years away. It belongs to the Alpha Centauri system, three stars that travel together: Alpha Centauri A and B, a bright pair about 4.34 light-years away, and the faint red dwarf Proxima. All three lie in the direction of the constellation Centaurus, a star pattern in the southern sky, and belong to our Milky Way galaxy. From most of the United States you cannot see them at all. The quick facts:

What is the closest star to Earth?

The Sun, of course. The next closest is Proxima Centauri, about 4.25 light-years away, based on its parallax from the Gaia space telescope listed in the SIMBAD database (our conversion). Parallax is the tiny shift in a star's position as Earth travels around the Sun; the smaller the shift, the farther the star. A light-year is the distance light travels in one year, about 9.46 trillion km, so Proxima is about 40.2 trillion km (25 trillion miles) from us.

Just a little farther away are Alpha Centauri A and B, at about 4.34 light-years. Among the other nearby stars are Barnard's Star (5.96 light-years), Wolf 359 and Lalande 21185. Sirius, the brightest star in the night sky, is about 8.6 light-years away (all from SIMBAD parallaxes, our conversion). Our chart shows a selection, not a complete list.

Alpha Centauri: three stars in one system

Alpha Centauri is a triple star system. To the eye it looks like one bright star, but it is really two stars, A and B, orbiting each other, plus Proxima far away. NASA says A is the same type of star as the Sun and slightly bigger, and B is slightly smaller. A 2016 study by Pierre Kervella and colleagues gives their masses as about 1.11 and 0.94 times the Sun's.

A and B go around each other once every 80 years. Using the orbit from that 2016 study, we calculated that their distance apart swings between about 11.3 and 35.8 au, where 1 au is the distance from Earth to the Sun. That is like a range from beyond Saturn's orbit to beyond Neptune's. They were physically closest in 1955 and will be again in 2035. Seen from Earth, the two look closest together a little later, in late 2037, because we see the orbit from the side (our calculation).

Proxima is much farther from the pair. From the SIMBAD distances and positions we calculated that it is about 12,000 au from A and B, or about 0.19 light-years, and about 2.18° away from them in our sky.

Proxima Centauri and its planets

Proxima Centauri is a red dwarf: a small, cool, faint star. ESA/Hubble describes it as roughly an eighth of the Sun's mass and too faint to see with the naked eye. It is a flare star, whose brightness can jump suddenly. SIMBAD lists its brightness as magnitude 11.13; on this scale, smaller numbers mean brighter objects. That is about 113 times fainter than the faintest stars you can see under a dark sky (around magnitude 6; our calculation), so you need a telescope. The Hubble picture shows the star itself, not its planets.

In 2016 ESO announced a planet around it, Proxima b, found from the tiny wobble it causes in the star's motion. ESO says it goes around its star every 11.2 days, about 7 million km from it, and "lies well within the habitable zone around the star", the zone where liquid water could exist on the surface. The discovery estimated at least 1.3 times Earth's mass; a 2025 study puts its minimum mass at about 1.06 times Earth's. ESO adds that liquid water there "cannot be ruled out", but also that the star sends out strong ultraviolet and X-ray flares. NASA's exoplanet catalog calls Proxima b a "super Earth", a size class, not a sign of Earth-like conditions. No atmosphere, oceans or surface temperature have been measured, and no oxygen has been detected on Proxima b.

In 2022 ESO reported another planet candidate, Proxima d, with about a quarter of Earth's mass and a five-day orbit; a 2025 study confirmed it. A further signal, Proxima c, with an orbit of about five years, remains unconfirmed. Around Alpha Centauri A and B no planet is confirmed: in 2025 NASA reported evidence from the Webb telescope for a gas giant about the mass of Saturn around A, but later Webb images did not show it again, so it remains a candidate. Is there life? Nobody knows; being in the habitable zone does not mean a planet is habitable. See is there life on other planets?

Can you see Alpha Centauri from the US?

Only from the far south. Alpha Centauri A and B sit about 61° south of the celestial equator (Earth's equator projected onto the sky), so they can only rise for places south of about 29° N; the bending of light near the horizon shifts that line a little (our calculation). Even there they stay low:

(Our calculation with Astronomy Engine, including the usual bending of light near the horizon; 0° is the horizon.) Nearby dates work too; the star then reaches its highest point a little earlier or later in the night. From Houston it stays just below the horizon, and from New York and most of the country it never rises. Proxima, farther south, can only rise south of about 27.2° N, reaching about 5.9° from Honolulu before refraction (our calculation), and it needs a telescope anyway.

To find it, wait for a clear night with a flat, open view to the south, around early summer evenings. Alpha Centauri is the brighter of two stars low in the south; the other is Beta Centauri, and the Southern Cross is nearby. Because it is so low, haze can easily hide it. From southern mid-latitudes it climbs much higher and is one of the brightest stars of all: SIMBAD lists A and B together at magnitude -0.1.

How long would it take to get to Alpha Centauri?

Far longer than a human life with today's spacecraft. Light from Proxima Centauri takes about 4.25 years to reach us. Voyager 1, the most distant spacecraft, travels at about 16.92 km/s relative to the Sun. Covering today's distance to Proxima at that speed would take about 75,000 years (our calculation, ignoring how the stars move). This is only a speed comparison: NASA says Voyager 1 is heading towards a different star, more than 17 light-years away.

To get there in 400 years, a spacecraft would need about 3,183 km/s, or 1.06% of the speed of light (our calculation). No spacecraft has come close to that. For comparison, NASA's New Horizons, launched in January 2006, needed until July 2015 just to fly past Pluto.

Alpha Centauri FAQ

Is Alpha Centauri the closest star to Earth? The Sun is Earth's closest star. Beyond our solar system, Alpha Centauri is the nearest star system, and Proxima is its nearest member, about 4.25 light-years away; A and B are about 4.34 light-years away.

What is a trinary star system? A system of three stars held together by gravity. In Alpha Centauri, A and B orbit each other every 80 years, and Proxima is far out, about 12,000 au from the pair (our calculation).

Can we see Alpha Centauri from Earth? Yes, from the Southern Hemisphere and the far south of the US, where A and B look like one bright star in the constellation Centaurus. Proxima needs a telescope.

What colour is Alpha Centauri A? A is the same type of star as the Sun (NASA), and ESO describes the pair as pale yellow, like the Sun.

How many planets does Proxima Centauri have? Two confirmed planets: Proxima b (2016) and Proxima d (reported in 2022, confirmed in 2025). A third signal, Proxima c, is unconfirmed. Note that Proxima b is a planet, while Alpha Centauri B is a star.

Could there be life there? Nobody knows. Proxima b is in the habitable zone, but its star sends out strong flares, and no signs of life have been found.

Would it take 400 years to get to Alpha Centauri? Only at about 1.06% of the speed of light. At Voyager 1's speed, a trip to Proxima would take about 75,000 years (our calculation).

Will Voyager 1 ever reach Proxima Centauri? No. NASA says Voyager 1 is heading towards a different star, more than 17 light-years away.

What is a red dwarf star? A small, cool and faint star, like Proxima, which ESA/Hubble says has roughly an eighth of the Sun's mass.

Looking north instead? Start with the Big Dipper.

How we checked

Star positions, brightness (V magnitudes) and parallaxes come from the SIMBAD database (CDS, Strasbourg), queried on 2 November 2026 through its official Harvard mirror; we turned parallaxes into light-years. The orbit of A and B comes from the elements published by Kervella and colleagues in 2016; we calculated positions from them and checked them against the study's measured positions: at five observing dates, our separations differed by no more than 0.071 arcsecond and the direction from A to B by no more than 0.57°. Heights above the horizon for US places and the 2027 dates when the star is highest around 10 p.m. are our calculations with the Astronomy Engine library. Travel times are simple distance-divided-by-speed calculations. Facts and images come from NASA, ESA/Hubble and ESO, and the planet updates from a 2025 study and NASA, listed under Sources. We checked all sources on 2 November 2026.

None of the images or videos is AI-generated, and we did not use artist's impressions.