Energy of Sun

[ImZ]

Enery don`t come into being and don`t disappear. But the enegy of Sun disappear time-to-time. Does somebody know about how many joules of energy Sun have right now? And what will happen if the energy of Sun ends.

[Stargazer]

The sun produces energy by nuclear fusion around 3.8 x 10^26 W I think it was. The energy doesn't disappear, but only a tiny part hits our planet, providing input of energy for life to exist etc. It is almost certain that the sun will last for another 5 billion or so years, but before that it will grow into a red giant before shrinking again to a white dwarf. Then how long that one will last, I'm not sure.

[sanctus]

During the nuclear fission there is production of gamma rays (photons). If I remember right this represents 0.7% of the energy disponible (much of it gets lost in neutrino i think). in addition to that the many of those gamma rays never make it out of the suns centers as they get absorbed before. So that where the enrgy disappears.

[Babbler]

I read it takes several thousand years for energy to travel from the core to the surface of the sun.

[pgrmdave]

I remember learning that the sun loses mass constantly because of the energy it gives off, but I forget the exact amount.

[Tim_Lou]

A quick search in google:

http://www.astronomycafe.net/qadir/q2182.html

"4 x 10^33 Watts"

 

hmm, but isnt the rate of fussion related to how many reactants presented? since the mass is decreasing, therefore the power should decrease from time to time... well, my guess is the affect isnt very significate, right?

[pgrmdave]

But there is so much hydrogen contained in the core that there is always more than 5 trillion grams of mass to be converted, and it's not as though this were all taking place in one isolated bubble at one time, it is taking place constantly throughout the core, more like a steady stream than a pulse.