NOAO >   Observing Info >   Approved Programs >   2011B-0001

Small NOAO Logo

Proposal Information for 2011B-0001


PI: Travis Metcalfe, High Altitude Observatory, travis@ucar.edu
Address: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, USA

CoI: Sarbani Basu, Yale University
CoI: Todd Henry, Georgia State University
CoI: Phil Judge, High Altitude Observatory
CoI: David Soderblom, Space Telescope Science Institute

Title: Activity Cycles of Southern Asteroseismic Targets

Abstract: The Mount Wilson Ca HK survey revealed magnetic activity variations in a large sample of solar-type stars with timescales ranging from 2.5 to 25 years. This broad range of cycle periods is thought to reflect differences in the rotational properties and the depths of the surface convection zones for stars with various masses and ages. Asteroseismic data will soon provide direct measurements of these quantities for individual stars, but many of the most promising targets are in the southern sky, while long-term magnetic activity cycle surveys have been confined to the north. We propose to continue a long-term monitoring campaign of Ca \sc ii H and K emission for a sample of 58 southern solar-type stars to measure their magnetic activity cycles, and their rotational properties when possible. This sample includes the most likely southern asteroseismic targets to be observed by the Stellar Observations Network Group (SONG), currently scheduled to begin operations in 2012. Our survey has already led to the discovery of the shortest known (1.6 year) activity cycle in a solar-type star, and several additional targets in our sample show promising short-term variations in the first three years of data.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2011B-0001

noaoprop-help@noao.edu

Small NOAO Logo