Facts about the sun
The Sun is the star at the center of the Solar System . It is a nearly perfect sphere of hot plasma , [18] [19] heated to incandescence by nuclear fusion reactions in its core, radiating the energy mainly as visible light , ultraviolet light , and infrared radiation. It is by far the most important source of energy for life on Earth . Its diameter is about 1.39 million kilometres (864,000 miles), or 109 times that of Earth. Its mass is about 330,000 times that of Earth; it accounts for about 99.86% of the total mass of the Solar System. [20] Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen , carbon , neon and iron . [21] Facts about the sun Sun Pictured in visible light dimmed with solar filter in 2013 with sunspots and limb darkening . False-color image taken in 2010 as seen in ultraviolet light (wavelength of 3