Alpha Centauri Extraterrestrials

Asteroseismic studies, chromospheric activity, and stellar rotation (gyrochronology) are all consistent with the Alpha Centauri system being similar in age to, or slightly older than, the Sun. Asteroseismic analyses that incorporate tight observational constraints on the stellar parameters for the Alpha Centauri stars have yielded age estimates of 4. 85±0. 5 Gyr, 5. 0±0. 5 Gyr, 5. 2 ± 1. 9 Gyr, 6. 4 Gyr, and 6. 52±0. 3 Gyr. Age estimates for the stars based on chromospheric activity (Calcium H & K emission) yield 4. 4 ± 2. 1 Gyr, whereas gyrochronology yields 5. 0±0. 3 Gyr. Stellar evolution theory implies both stars are slightly older than the Sun at 5 to 6 billion years, as derived by their mass and spectral characteristics.

a b c d e f g h i j k l m n o p q r s t u v w x y z