102 citations · 438 across the 14 of their papers we have counts for
14 papers
Solar-Cycle Variation of quiet-Sun Magnetism and Surface Gravity Oscillation Mode
Maarit J. Korpi-Lagg, Andreas Korpi-Lagg, Nigul Olspert +1
The origin of the quiet Sun magnetism is under debate. Investigating the solar cycle variation observationally in more detail can give us clues about how to resolve the controversi…
A Knee-Point in the Rotation-Activity Scaling of Late-type Stars with a Connection to Dynamo Transitions
Jyri J. Lehtinen, Maarit J. Käpylä, Nigul Olspert +1
The magnetic activity of late-type stars is correlated with their rotation rates. Up to a certain limit, stars with smaller Rossby numbers, defined as the rotation period divided b…
Common dynamo scaling in slowly rotating young and evolved stars
Jyri J. Lehtinen, Federico Spada, Maarit J. Käpylä +2
One interpretation of the activity and magnetism of late-type stars is that these both intensify with decreasing Rossby number up to a saturation level, suggesting that stellar dyn…
Shapes of stellar activity cycles
T. Willamo, T. Hackman, J. J. Lehtinen +4
Magnetic activity cycles are an important phenomenon in both the Sun and other stars. The shape of the solar cycle is commonly characterised by a fast rise and a slower decline, bu…
Sensitivity to luminosity, centrifugal force, and boundary conditions in spherical shell convection
Petri J. Käpylä, Frederick A. Gent, Nigul Olspert +2
We test the sensitivity of hydrodynamic and magnetohydrodynamic turbulent convection simulations with respect to Mach number, thermal and magnetic boundary conditions, and the cent…
Estimating activity cycles with probabilistic methods II. The Mount Wilson Ca H&K data
N. Olspert, J. Lehtinen, M. J. Käpylä +2
Debate over the existence of branches in the stellar activity-rotation diagrams continues. Application of modern time series analysis tools to study the mean cycle periods in chrom…