Alpha Centauri B
The cooler orange companion in the Alpha Centauri pair, 80 years to a single orbit.
Where it is right now
Alpha Centauri B is in Centaurus, 276046.8 AU away.
Computed for 2 August 2026, 20:00 UTC, and recomputed at least hourly. This page is cached, so treat the line above as accurate to the hour rather than to the second. The map shows the live position.
Position from a Kepler propagation of the published elements below, accurate to about an arcminute.
Facts
Every line carries the source it came from.
- Distance
- 4.365 light years, about 276,000 AUSource: SIMBAD / Hipparcos, J2000 astrometry
- Type
- K1V orange dwarf, 91 percent of the Sun's massSource: SIMBAD / Hipparcos, J2000 astrometry
- Radius
- about 602,000 km, 0.86 times the Sun'sSource: SIMBAD / Hipparcos, J2000 astrometry
- Apparent magnitude
- 1.33Source: SIMBAD / Hipparcos, J2000 astrometry
- Separation
- 11 to 36 AU from Alpha Centauri A over each 80 year orbitSource: SIMBAD / Hipparcos, J2000 astrometry
- X-ray output
- brighter in X-rays than its larger companionSource: ESO / NASA Exoplanet Archive
Physical size
- Mean radius
- 601,700 km
- Diameter
- 1,203,400 km across
Orbit
Elements are heliocentric, referred to the J2000.0 ecliptic.
- Average distance from the Sun
- 276,047.0 AU
- Eccentricity
- 0.0000, almost perfectly circular
- Inclination to the ecliptic
- -42.60 degrees
- Orbital period
- 999.3 million years
- Longitude of ascending node
- 149.47 degrees
- Argument of periapsis
- 90.00 degrees
- Mean anomaly at J2000.0
- 0.00 degrees
Claim this body
$499 per year
Proxima Centauri and the Alpha Centauri pair. Opens when the map expands past the solar system. Leased annually.
Wave 4 is not open yet, so this body is not for sale today. Wave 1 is.
A claim is a listing on this map. Not an IAU designation. Permanent, with one disclosed exception for dead links: see the terms.
Catalog id alpha-centauri-b. 3,172 objects on the map, of which 171 are hand-authored with sourced facts.