How much energy is lost from stars(including our sun) IN space?

Answer 1

no energy is ever lost, hence the law of conservation of energy. but, there is energy that never makes it to our planet, if that's what you mean. when the sun transforms hydrogen and helium molecules into radiation, it escapes through the stellar atmosphere, which is very thick, and while doing this, photons of radiation are bounced, absorbed, reflected, and all sorts of things before they actually reach a planet. but, in general, no energy is ever LOST in the sense of actually disappearing from this universe.

Answer 2

Just about all the output of stars radiates into space without doing anything in particular. Only a tiny fraction falls on a planet.

Answer 3

I think there shouldn't be any lost of energy, just being transformed from one form to another. potential to kinetic to chemical, that sort of changes.