In a <strong>systematic analysis of fully convective stars observed with TESS</strong>, we detected four stars that displayed giant <strong>flares that were...
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PublicationGiant white-light flares on fully convective stars occur at high latitudes
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PublicationInstrumental polarization in the focal plane of telescopes. 2: Effects induced by seeing
This work quantifies the influence of the terrestrial atmosphere on the instrumental polarization (IP) of telescopes. Our numerical simulations show that seeing...
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PublicationNon-local thermodynamic equilibrium line profiles, rotation, and magnetic fields in seven DA white dwarfs
Non-LTE calculations of H-alpha line profiles are presented and applied to derive rotational velocities from high-resolution spectra of DA white dwarfs. This...
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PublicationObserved differences between large and small sunspots
We confirm recent results about the differences in temperature and magnetic field strength between the umbra of large and small sunspots. Five Stokes I- and V...
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PublicationThe age decay of stellar magnetic activity in MS field solar-type stars
The age decay of two indicators of the stellar magnetic activity (λ2800 Mg II emission flux and λ10830 He I equivalent width) have been studied for field solar...
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PublicationThe magnetic field of the AP star Epsilon UMa
The magnetic field of the Ap star Epsilon UMa was measured using the Zeeman-Doppler Imaging method. Ultrahigh S/N polarized profiles of the 4923 A magnetically...
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PublicationThe Origin of Weakened Magnetic Braking in Old Solar Analogs
The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. The rate of angular momentum...