edu.ucar.opensky::articles:6105 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T15:34:21.950581 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7k64j7r Asteroseismic signatures of stellar magnetic activity cycles 2007-07-01T00:00:00Z publication https://n2t.org/ark:/85065/d7k64j7r https://doi.org/10.1111/j.1745-3933.2007.00325.x Metcalfe, Travis author Dziembowski, W. author Judge, Philip G. author Snow, M. author UCAR/NCAR - Library publisher Observations of stellar activity cycles provide an opportunity to study magnetic dynamos under many different physical conditions. Space-based asteroseismology missions will soon yield useful constraints on the interior conditions that nurture such magnetic cycles, and will be sensitive enough to detect shifts in the oscillation frequencies due to the magnetic variations. We derive a method for predicting these shifts from changes in the MgII activity index by scaling from solar data. We demonstrate this technique on the solar-type subgiant β Hyi, using archival International Ultraviolet Explorer spectra and two epochs of ground-based asteroseismic observations. We find qualitative evidence of the expected frequency shifts and predict the optimal timing for future asteroseismic observations of this star. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2007 Authors. Published under license by John Wiley & Sons for the Royal Meteorological Society. The definitive version is available at http://onlinelibrary.wiley.com. None eng geoscientificInformation