Size comparison: Alpha Centauri A vs Sun

Size comparison between the two stars, Alpha Centauri A and the Sun.

Alpha Centauri A is the main star of the three stars that form the Alpha Centauri system. She is also called Rigil Kentaurus. It is one of the closest stars to Earth. Its characteristics are very close to those of our star. However, the quantity of metals present in the star is twice that of the Sun. Its mass is greater by 10% and its radius is greater by 23%.

No planet has been detected around this solar system, that said the James-Webb Space Telescope should make it possible to find planets whose radius is at least 5 times greater than that of the Earth. In May 2028, Alpha Centauri will pass in front of a supergiant star S5, which will create a microlensing event and help highlight some planets in this solar system.

In James Cameron's film Avatar, the natural satellite Pandora orbits a gas giant planet that orbits the star Alpha Centauri A.

Object	Alpha Centauri A	Sun
Type	Star, yellow dwarf	Star, yellow dwarf
Age	6.8 billion years	4.6 billion years
Diameter	1,708,820 km	1,392,684 km
Mean radius	854,411 km	696,342 km
Mass	2.17 × 1030 kg	1.98 × 1030 kg
Surface gravity	199.53 m/s²	274.4 m/s²
Circumference	5.4 million km	4.3 million km
Surface area	0.91 × 1013 km2	6.09 × 1012 km2
Volume	2.6 × 1018 km3	1.41 × 1018 km3
Sun distance	4.3 light years	0 km
Luminosity	5.76 × 1026 W	3.82 × 1026 W
Photosphere temperature	5,800 K	5,772 K
Distance from the Milky Way center	27,200 light years	27,200 light years
Metallicity	0.028	0.0122
Spectral classification	G2 V	G2V
Absolute magnitude	4.38	4.83
Right ascension	14h 39m 35,88s	19h 4m 30s
Declination	−60° 50′ 13,4″	+63.87°

Note: if one of the objects is not visible, it just means that it is too tiny to be displayed compared to the other one.