Publications (19)
Differences in the solar cycle variability of simple and complex active regions during 1996-2018
Shabnam Nikbakhsh, Eija Tanskanen, Maarit Käpylä +1
Aims. Our aim is to examine the solar cycle variability of magnetically simple and complex active region. Methods. We studied simple ( and ) and complex ( and $βγδ…
Dependence of the large-scale vortex instability on latitude, stratification and domain size
Maarit J. Mantere, Petri J. Käpylä, Thomas Hackman
In an earlier study, we reported on the excitation of large-scale vortices in Cartesian hydrodynamical convection models subject to rapid enough rotation. In that study, the condit…
Magnetic evolution of complex solar active regions
Shabnam Nikbakhsh, Eija I. Tanskanen, Thomas Hackman
Aims. This study investigates the magnetic evolution of solar active regions (ARs), with a particular focus on understanding how the magnetic morphology of simple and complex ARs c…
Spot evolution on LQ Hya during 2006--2017: temperature maps based on SOFIN and FIES data
Elizabeth M. Cole-Kodikara, Maarit J. Käpylä, Jyri J. Lehtinen +4
Context. LQ Hya is one of the most frequently studied young solar analogue stars. Recently, it has been observed to show intriguing behaviour by analysing long-term photometry: dur…
Starspot activity of HD 199178. Doppler images from 1994--2017
Thomas Hackman, Iya Ilyin, Jyri J. Lehtinen +4
Context. Studying the spots of late-type stars is crucial for distinguishing between the various proposed dynamo mechanisms believed to be the main cause of starspot activity. For…
Multiperiodicity, modulations and flip-flops in variable star light curves III. Carrier fit analysis of LQ Hya photometry for 1982-2014
Nigul Olspert, Maarit J. Käpylä, Jaan Pelt +4
We study LQ Hya photometry for 1982-2014 with the carrier fit (CF) -method and compare our results to earlier photometric analysis and recent Doppler imaging maps. We first utilize…