Evidence for long-term brightness changes of solar-type stars

  title={Evidence for long-term brightness changes of solar-type stars},
  author={Sallie L. Baliunas and Robert Jastrow},
CHANGES in the brightness of the Sun may introduce further uncertainties into forecasts of global warming by the greenhouse effect. The Sun is known to vary in brightness, on a timescale of years, by 0.1% in phase with changes in magnetic activity during the solar cycle1–3, and variations of up to 0.4%, also correlated with surface magnetic activity, have been found in stars similar to the Sun4. To delimit the magnitude of solar luminosity variations on a timescale of centuries, we have looked… CONTINUE READING