The Sun loses millions of tons of mass every second.
Why it is true
Through nuclear fusion and solar wind, our star constantly converts and ejects matter into space, although this loss is insignificant compared to its total mass.
Source: NASA
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.