HD 23630: (u, v) plan coverage, differential visibilities (δV), differential phases (δϕ) and closure phases (CP) from our HR measurements. Each observation in the (u, v) plane, i.e., three baseline measurements, is plotted with a different color and symbol: blue circles correspond to the baselines B₁–B₃; green squares to baselines B₄–B₆; red triangles to baselines B₇–B₉; purple diamonds to baselines B₁₀–B₁₂; pink hexagons to baselines B₁₃–B₁₅; cyan pentagons to baselines B₁₆–B₁₈; orange thin diamonds to baselines B₁₉–B₂₁. See description in Sect. 4.