Treffer: A Python Toolkit for Plotting Double Star Observations with 1:1 Aspect Ratio

Accurate visualization of double star astrometric data is essential for effective analysis and interpretation. This article presents a Python toolkit designed for astronomers who need to plot measurements from diverse sources -- historical, Gaia DR3, and the Las Cumbres Observatory (LCO) network -- while maintaining a 1:1 aspect ratio to avoid visually distorting the data. The toolkit is composed of three scripts: one that handles polar coordinates (P.A., separation), one for Cartesian (X, Y) coordinates, and another with the option to include predicted theoretical points. This paper describes the purpose, functionality, and usage of these scripts, including example figures, installation guides, and licensing information. This toolkit has been used by the author and collaborators in published and submitted research on double star systems, demonstrating its versatility for both professional and student-driven investigations.
Comment: 7 pages, 1 figure