A technique for measuring solar differential rotation

Journal of the British Astronomical Association, Volume 136, Issue 3, pages 180–185 (2026); DOI: TBC

A B S T R A C T

The Sun exhibits differential rotation, with its rotation rate or period varying with heliographic latitude. This short paper demonstrates a method for using full-disc white-light solar images to measure the Sun’s rotation rate at different latitudes. Using images from the Solar Dynamics Observatory, suitable sunspots are selected. The central meridian distance of these sunspots is calculated, and the synodic rotation rates are determined. The paper also explains how to convert synodic to sidereal rotation rates and derive parameters for a differential rotation model. Results are compared with other studies, showing consistency despite the relatively small number of measurements.


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