Name/Affiliation: Sandra Jeffers (Goettingen University)
The Bcool magnetic snapshot survey of solar-type stars
Stellar magnetic field measurements obtained from spectropolarimetry offer key data for activity and dynamo studies, and we present the results of a major high-resolution spectropolarimetric Bcool project magnetic snapshot survey of nearly 200 solar-type stars from observations with the Telescope Bernard Lyot and the Canada-France-Hawaii Telescope. Surface magnetic fields were detected for one third of our sample, including surprising detections on a few subgiant stars. In this talk we will show how the magnetic field strength (longitudinal field) is correlated with basic stellar parameters such as rotation rate, age, chromospheric activity indicators as well as with spectral type. This survey constitutes the most extensive spectropolarimetric survey of cool stars undertaken to date, and suggests that it is feasible to pursue magnetic mapping of a wide range of moderately active solar-type stars to improve understanding of their surface fields and dynamos.