PI: Mark S. Giampapa, NOAO, email@example.com
Address: NSO, 950 N. Cherry Ave./PO Box 26732, Tucson, AZ 85726-6732, USA
CoI: Richard R. Radick, AFGL
CoI: Jeffrey C. Hall, Lowell Observatory
CoI: Sallie L. Baliunas, SAO
Title: Cycles and Long-Term Variability in Solar-Type Stars
Abstract: We propose a long-term extension of our current WIYN/Hydra program to study chromospheric activity cycles in the `Suns of M67.' Our results thus far have revealed that the distribution of activity among the solar- type stars in M67 is broader than what would be expected from a comparison with the solar cycle. The next step is to determine whether our results arise from the cyclic modulation of activity alone \it or if the relative amplitudes of cycles in solar-type stars and the Sun are actually similar and the spread in M67 is due to differences in the \it mean level of activity. Only a long-term monitoring program of regular observations can address these questions. The results of this program are expected to reveal all the potential modes and amplitudes of magnetic cycles in sun-like stars and, by inference, in the Sun itself, with important implications for dynamo models and models of global climate change.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360