Cool Stars 14 - Submitted Abstract # 59
This version created on 05 October 2006

Synoptic Observations of Cycling and Flat Activity Solar Analog Stars


Jeffrey Hall, Lowell Observatory
G. Wesley Lockwood, Lowell Observatory
Brian Skiff, Lowell Observatory

We present the primary results of a decade of observations of bright
solar analogs with Lowell Observatory's Solar-Stellar Spectrograph.
We discuss both the general characteristics of the magnetic activity
and variability in our 143-star ensemble, and on detailed results for
stars of particular interest.  In particular, we (1) derive an
improved cycle period for the solar twin 18 Scorpii, (2) present
evidence for the secular evolution of magnetic activity at successive
cycle minima in the bright binary HD 81809, (3) present observations
showing what appear to be significant transitions between cyling and
flat activity (putative Maunder minimum) states, and (4) discuss the
absence of any significant correlation, among the best-observed solar
analogs, between the presence or absence of an activity cycle and the
overall excess magnetic flux.

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