Comet Tail Analyzer: A GUI Tool for Finson–Probstein Dust-tail Modeling

Abstract I present Comet Tail Analyzer , an open-source Python graphical application for projecting Finson–Probstein syndyne and synchrone grids onto comet images. Operating as a forward-modeling tool, the software computes and overlays dust-particle loci on user-supplied astronomical images using observing geometry retrieved from JPL Horizons. The tool allows observers to identify candidate particle-size ranges and emission ages by comparing syndynes ( β ) and synchrones with the observed tail morphology. Images with World Coordinate System information can be used directly; PNG and JPEG images are supported when the image scale and north position angle are supplied. As a demonstration, I apply the tool to pre-perihelion observations of C/2023 A3 (Tsuchinshan–ATLAS), showing that syndyne overlays for β ≈ 0.01–0.05 correspond to particle radii of ∼24–120 μ m, with the lower end close to the ∼20 μ m minimum particle radius inferred from published dust-dynamical modeling of the same comet.