- Merry Christmas and Happy New 2013 Year
- Site anouncement
- Doomsday on 21 December 2012 - End of the world or the day of misunderstanding?
- And cameras are back
- We have changed our hosting.
- The observatory is off the Internet
- Merry Christmas and Happy New 2012 Year
- Iridescent cloud over the Rila Mountain
- Site changes
- Quadrantids meteor shower 2011
|Submitted by nikipetrov on 6 May, 2009 - 21:41|
The core makes about 2% of the Sun’s volume (core’s radius is ~1/4 Rסּ) but contains nearly half of its mass. The highest temperature is in the center ~1.55x107 and decreases outwards to 9.42x106 K. The high temperatures and densities provide conditions for the nuclear fusions that power the Sun. Most energy is provided from the three step process of hydrogen to helium conversion (proton-proton chain). A single proton-proton chain yields 26.73 MeV in gamma rays and ~0.5 MeV in two neutrinos.