Distribution of the longitude of coronal off-limb structures over a 27-day period in 2021, shown for different latitude belts: centred around 40° in the northern hemisphere (panel b) and −40° in the southern hemisphere (panel c), with a latitude range of ±5°. Panel (a) shows the longitudinal distribution simultaneously centred around 40° latitude in the northern hemisphere and −40° latitude in the southern hemisphere, also with a latitude range of ±5°. These latitude belts correspond to the solar regions rotating with an approximately 27-day period, while lower latitudes rotate faster and higher latitudes rotate more slowly. (a) Latitude belt at ±35°/±45°. (b) Latitude belt between 35° and 45°. (c) Latitude belt between −45° and −35°.