A series of 35 high-resolution spectra are used to measure the third-signature plot of the G8?III star, ζ?Cygni, which shows convective velocities only 8% larger than the Sun. Bisector mapping yields a flux deficit, a measure of granulation contrast, typical of other giants. The observations also give radial velocities with errors ~30?m?s–1 and allow the orbit to be refined. Velocity excursions relative to the smooth orbital motion, possibly from the granulation, have values exceeding 200?m?s–1. Temperature variations were looked for using line-depth ratios, but none were found.
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