We can observe stars to better understand our own Sun, exploring its variability and its effects on Earth’s environment and climate.
Thirty years ago, stimulated by the new knowledge that the Sun’s brightness variations over the 11-year solar cycle were less than 0.1 percent, Wes Lockwood, Brian Skiff, and their colleagues began a systematic photometric study of the small brightness fluctuations of sunlike stars of various ages. Using the 21-inch telescope and a dedicated photometer, Brian Skiff observed several dozen sunlike stars for 16 consecutive seasons, finding that a majority of sunlike stars have detectable year-to-year variations from as small as 0.3 percent to several percent; (2) the amount of variability decreases with increasing stellar age.
Wes, Jeff Hall, Brian Skiff, and Len Bright have also observed these stars spectroscopically since 1994 using Lowell’s Solar-Stellar Spectrograph, an instrument fed by an optical fiber from a solar feed and from the 1.1-m J. S. Hall telescope at Anderson Mesa. It is intended to characterize the magnetic activity of these stars and the Sun on the timescale of the 11-year solar cycle.