Spectral Variations of the Sun During the Recent Cycle Minimum
Jeffrey C. Hall [jch@lowell.edu], G. Wesley Lockwood, Brian A. Skiff, and Leonard P.
Brigh, Lowell Observatory, Flagstaff, Arizona
We have continued our calcium H&K and echelle monitoring of the Sun throughout the
long Cycle 23/24 minimum. Observations since August 2008 have been made with new
CCD cameras, allowing both an improved characterization of solar variability at minimum
activity, as well as a careful re-examination of our older data, which include the previous
minimum of cycle 22/23. We will present the behavior of the current minimum both in terms
of the usual activity indices (Mount Wilson S and the chromospheric flux fraction log R’) as
well as dynamo-related magnetic flux, and compare the two cycle minima we have now
observed. Additionally, we discuss the observed solar variations from 2008-2010 with those
of several Maunder Minimum candidate stars on our stellar program.