Cool Stars 14 - Submitted Abstract # 203 This version created on 05 October 2006 The Kepler Mission: Terrestrial Exoplanets and Stellar Activity Gibor Basri, UC Berkeley Francisco Ramos-Stierle, UC Berkeley Kurt Soto, UC Santa Barbara Tristan Lewis, UC Berkeley Ansgar Reiners, MPI fuer Sonnensystemforschung William Borucki, NASA Ames Research Centers David Koch, NASA Ames Research Center Kepler is a NASA Discovery mission designed to determine the frequency and distribution of Earth-sized planets within 1 AU of F-M main sequence stars. This is done by searching for planetary transits. The mission will return up to 150,000 broad-band light curves with unprecedented precision (20 micromag) and 30 minute resolution, that are virtually continuous for several years. Along with a program to determine precise stellar parameters, the size and orbital distance of the planets can be estimated, as well as the relations between planets and the stars they orbit. By the end, at least several hundred terrestrial planets should be discovered if they are common. A null result would strongly imply that terrestrial planets are rare. The Kepler dataset is obviously also a treasure-trove of information on stellar activity and rotation. We have begun a research program to understand and simulate stellar microvariability. We start by trying to understand the Sun as a microvariable star (cf. the poster by Soto et al.). Having derived laws which govern continuum variability as a function of magnetic configurations, we have also begun to determine what utility these simulations might have. Possibilities include finding rotation periods (not always easy!), understanding the appearance of stars viewed at different inclinations (can we actually derive inclination?), extraction of magnetic distributions in longitude and latitude, size- and time-scales for active regions and starspots. There will be an opportunity for Guest Investigators to propose targets that are not part of the exoplanet search. Kepler can lead to a great leap in our understanding of the behavior of stellar activity as a function of stellar mass and age. ----------------------------------