How the Sun loses mass

The Sun loses mass through both the solar wind and conversion of mass into energy by nuclear fusion. The wind carries away roughly one billion kilograms per second—an order-of-magnitude estimate consistent with the claim, though the rate varies. Separately, emitted radiation corresponds to about 4.3 billion kilograms of mass-energy each second. It is important to distinguish matter expelled by the solar wind from mass equivalent to radiated energy. The illustration is AI-generated.