Observations of a solar latitude-dependent limb brightness variation

A small latitude-dependent photospheric excess brightness variation has been observed from 131 days of data obtained with the Princeton Solar Distortion Telescope. Using an analytic model to separate the influence of faculae from the brightness signal, a temperature difference of 0.6 + or - 0.1 K between the poles and the regions at + or - 53 solar latitude was obtained for the summer of 1983, a temperature difference of 0.6 + or - 0.1 K between the poles and the regions at + or - 53 deg solar latitude was obtained for the summer of 1983, with the polar regions being hotter.