Orbital motion. Top: Two Keplerian orbits from γ Cep B and γ Cep Ab shown in red and purple, respectively, and the 1 yr signal shown as the brown curve. The sum of the signals is shown as the grey model. Here they have all been shifted to start at 0.0 to make it easier to compare them. The Tenerife data are shown in blue and orange, and the Delingha data are shown in green. Bottom: Residuals after subtracting the model.