The Sun

Our star is a mass of hot, ionized gas, or plasma.  Fusion of hydrogen nuclei into helium in the Sun's core releases the energy which makes it hot.  This has gone on for 4.5 billion years, and will continue for another 5 billion years.

This false-color image from the Solar and Heliospheric Observatory (SOHO) shows extreme UV light which can't reach Earth's surface.  The bright area at lower center was the site of a solar flare.


Physical Properties
Diameter1,392,530 km=    109  Earth diameters
Radius696,265 km
Mass1.98843 x 1030 kg    =    332,946  Earth masses
Mean density1.41 g/cm3
Rotational period25.38 days  at equator  to  35 days  at poles
Gravity at visible surface273 m/s2
Escape speed618 km/sfrom visible surface
Visual magnitude (Vo)-26.8as seen from Earth
Mean surface temperature    6000C

Composition
Hydrogen    92.1%
Helium7.8%
Oxygen0.061%
Carbon0.030%
Nitrogen0.0084%
Neon0.0076%
Iron0.0037%
Silicon0.0031%
Magnesium    0.0024%
Sulfur0.0015%
Other0.0015%


HomeTo my Space and Science home page  for more about the Solar System

Jeff Root
September 4, 2003