Image Details
Caption: Figure 2.
Left: continuum image with sunspot, middle: magnetogram with active regions, both registered at the same time (00:00 UT) on 2012 November 1 by HMI/SDO. Right: μ map, which represents the cosine of the heliocentric angle that characterizes the pixel position on the solar disk.
© 2026. The Author(s). Published by the American Astronomical Society.