The data is a result from an analysis of the solar differential rotation (DR) during solar cycle No. 25 (SC25) (2020─2025), based on the Kanzelhöhe Observatory for Solar and Environmental Research (KSO) data set. The white-light images were processed and positions of sunspot groups were extracted using the morphological image processing technique. The sample was constrained to ±58° in central meridian distance (CMD). Two methods were applied to derive the sidereal angular rotation rate (ω) and, in turn, the solar rotation parameters A and B: (a) calculating synodic rotation velocities from daily CMD differences and elapsed time (daily shift method); (b) applying a robust linear least-squares fit to the time series CMD(t) for each sunspot group. More details about the whole procedure to extract sunspot positions and velocities can be found in Poljančić Beljan I. et. al. 2025 or Poljančić Beljan I. et. al. 2022

Sunspot positions

The Zurich Classification was extracted from Solar Regions Summaries published by SWPC - NOAA. Therefore the spot type is sometimes differing from KSO spot types in the drawings, if no NOAA position could be assigend the spot type is not available.

Sidereal Angular Rotation

The sidereal (ω_sid) and synodic (ω_syn) velocities for a date range can be selected from one of the two methods, the daily shift (DS) method or the least squares fit method. The number of datasets for the robust least square fit (rLSQ) is smaller as at least 3 postions for each spot group are needed to calculate the slope of the linear fit.