Contribution of Solar Mass Loss to the Solution the Faint Young Sun Paradox for Physically Motivated Mass Loss Prescriptions

Abstract

I consider the maximum contribution of mass loss and uncertainties in the standard (no mass loss) solar model to the resolution to the faint young sun paradox. I first consider the degree to which the past luminosity evolution of the sun could have differed from the prediction of the standard solar model by generating solar luminosity histories using alternate input physics and variations in the solar parameters. I find negligible variations (maximum of 0.602%) in the solar luminosity history for reasonable variations in the input physics and solar parameters, consistent with prior work. I also consider various physically motivated and ad hoc models for the mass loss history of the sun, which can in principle resolve the paradox by making the early sun more massive, and thus more luminous. I show that for reasonable physically motivated mass loss prescriptions, the luminosity evolution for most of the sun’s lifetime is unaffected. This upper limit on potential mass loss of the sun can be used to calibrate the extent to which the atmosphere and surface of the early Earth must differ from the present day in order to resolve the paradox.