Theoretical interpretation of solar and stellar irradiance variations

摘要: The main cause of variability solar type stars are their varying magnetic fields. To compute irradiance variations one has to the field (the dynamo problem), and from this effects. second problem is considered here. theoretical work past decade shown that dominant effect fields a surface effect: change effective emissivity parts while nonmagnetic part contributes very little variation on almost all time scales. No other processes have yet been found would exceeding (at current level activity) observed 0.1% fluctuation Sun. This implies knowledge [separated into its bright small scale (faculae, network) dark large (spots) components] sufficient for pre- or postdicting irradiance. It hypothesized discrepancy remaining between measured values reconstructed proxies due difficulty finding proxy accurately correlates with continuum contrast dispersed field. Stellar structure theory predicts in radius associated activity quite small. For stars, color brightness should primarily be interpreted terms fraction covered by patches. Their (long term) displacement sequence not large.