Alpha Centauri A & B compared to the Sun

Two Sun-like stars that look like one bright star to the eye and split apart in any small telescope.

How long do Alpha Centauri A & B take to go round each other?

Alpha Centauri A & B take about 80 Earth years to go once round each other. That is a whole human lifetime.

Alpha Centauri A & B have roughly two times the mass of the Sun.

You see Alpha Centauri A & B as they were 4.344 years ago.

Why it stands out: The nearest star system to the Sun, together with Proxima. Pairs like it are common: nearly half of Sun-like stars in the galaxy have a companion star.
How much light it gives off: A: 1.506 solar luminosities; B: 0.4981 solar luminosities.
What it is: Two Sun-like stars (one slightly bigger/hotter, one slightly smaller/cooler) locked in a close orbit, forming one bright naked-eye “star”.
How it moves: Their orbit is stretched: at their closest the two are a little farther apart than Saturn is from the Sun, at their farthest not quite as far as Pluto.; How we know: Astronomers have tracked the two stars’ positions for over a century, and the orbit they trace obeys Kepler’s and Newton’s laws. Rung 5 of the cosmic ladder — the distance to nearby stars

The numbers