SunSketcher: Precise Measurement of the Solar Shape via a Network of Smartphone Eclipse Observations: The shape of the solar limb is determined by sub-surface flows that reflect not only solar differential rotation, but also an assortment of other flow patterns associated with the 22-year solar cycle, the emergence of active regions, and so forth. The goal of the citizen science SunSketcher project is to measure the size and shape of the Sun to an unprecedented level of accuracy (a few parts per million), in order to constrain these flow fields.
Gordon Emslie is Professor, and SunSketcher Project Lead, at Western Kentucky University's Physics and Astronomy department..