We survey 223 916 auroral records from the Northern hemisphere observed between 1650 January and 2024 July, making full allowance for the secular change in the...

An analysis of high-resolution Stokes observations of two light bridges in the active region NOAA 8990 is presented. The observations were recorded with the La...

We describe the work carried out to obtain observational evidence of a local relation between the temperature and the magnetic field in different regions of...

Sunspots are intense regions of magnetic flux that are rooted deep below the photosphere. It is well established that sunspots host magnetohydrodynamic waves...

Context. The physical parameters of the sunspot are not fully understood, especially the height dependence of the magnetic field. So far, it is also an open...

The distribution of sunspot decay rates is studied using the Greenwich Photoheliographic Results (GPR) for a total of approximately hundred years between 1874...

An analytical model has been developed to empirically study the effects of stellar spots and faculae on the observed equivalent widths of Li i 6708, Na i 5896...

We determine the entire electrical current density vector in a geometrical three-dimensional volume of the inner penumbra of a sunspot from an inversion of...

We present an analysis of the Evershed effect observed with a resolution of 0.2". Using the new Swedish 1 m Solar Telescope and its Littrow spectrograph, we...