Finson–Probstein model overlays for C/2023 A3 (Tsuchinshan–ATLAS) on 2024 May 8 (r_h = 2.659 au, Δ = 1.794 au, phase ﹩=12\mathop{.}\limits^{^\circ }1﹩) produced by Comet Tail Analyzer. Left: syndynes for β = 0.01–1.0 (solid curves, β = const). Right: synchrones at emission ages of 10–180 days (dashed curves, age = const). The yellow arrow indicates the projected solar direction and the dashed blue line marks the orbital path. Syndynes for β ≈ 0.01–0.05 align with the observed dust-tail ridge, corresponding to particle radii of ∼24–120 μm for Q_pr = 1 and ρ = 1 g cm⁻³. The lower bound (∼24 μm) is close to the ∼20 μm minimum particle radius inferred by B. Liu et al. (2025).