The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2×1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. The rest of it (1.69%, 5,628 times the mass of Earth) consists of heavier elements, including oxygen,carbon, neon, iron, and others.
| Mean diameter |
1.392×106 km
109 × Earth |
| Equatorial radius |
6.955×105 km
109 × Earth |
| Equatorial circumference |
4.379×106 km
109 × Earth |
| Flattening |
9×10−6 |
| Surface area |
6.0877×1012 km2
11,990 × Earth |
| Volume |
1.412×1018 km3
1,300,000 × Earth |
| Mass |
1.9891×1030 kg
333,000 × Earth |
| Average density |
1.408×103 kg/m3 |
| Density |
Center (model): 1.622×105 kg/m3
Lower photosphere: 2×10−4 kg/m3
Lower chromosphere: 5×10−6 kg/m3
Corona (avg.): 1×10−12 kg/m3 |
| Equatorial surface gravity |
274.0 m/s2
27.94 g
28 × Earth |
Escape velocity
(from the surface) |
617.7 km/s
55 × Earth |
| Temperature |
Center (modeled): ~1.57×107 K
Photosphere (effective): 5,778 K
Corona: ~5×106 K |
| Luminosity (Lsol) |
3.846×1026 W
~3.75×1028 lm
~98 lm/W efficacy |
| Mean Intensity (Isol) |
2.009×107 W·m−2·sr−1 |
