Published online by Cambridge University Press: 12 April 2016
Using a nine-year time series of photometric observations of 33 stars similar in temperature and mass to the Sun, but covering a wide range of age and mean chromospheric activity, we found that a majority varies from year to year, some by as much as several percent. We describe the methodology, circumstances of the observations, and photometric results. Stars most similar in mean chromospheric activity to the Sun varied by amounts several times greater than the Sun over a comparable time interval. Thus, the Sun’s present low level of variability, as measured from 1980 to 1989 by the Solar Maximum Mission, appears unusual.