Alpha Centauri A
Star
Facts
- Distance
- 4.34 light-years
- Spectral class
- G2 V
- Diameter
- 1.22 times the Sun
- Mass
- 1.08 times the Sun
- Apparent magnitude
- −0.01
- Orbit with B
- 79.8 years
- IAU name
- Rigil Kentaurus
Alpha Centauri A is a yellow dwarf of spectral class G2 V, the same as the Sun, and the main star of the star system closest to us. Its surface temperature is almost identical to the Sun's, but it is a little larger and heavier: it has 8% more mass and shines about one and a half times as brightly.
Alpha Centauri A and B circle each other in about 80 years, and little Proxima Centauri, gravitationally bound to the pair, orbits both of them in about 550,000 years.
To the naked eye A and B appear as a single point: together they are the third brightest star in the night sky, after Sirius and Canopus.
Sources
- Akeson et al. 2021, AJ 162, 14 (orbit of Alpha Centauri A and B, table 8)
- Hoffleit and Warren 1991, Yale Bright Star Catalogue, 5th Revised Ed. (V magnitudes, positions and spectral classes)
- IAU WGSN, IAU Catalog of Star Names
- Kervella, Thévenin and Lovis 2017, A&A 598, L7 (Proxima's orbit around Alpha Centauri)