Assessment of the Absence of Magnetic Measurements for the Interstellar Object 3I/ATLAS: A Comprehensive Review of Published Data and Archival Resources (V2 APS Edition)

Abstract — The interstellar object 3I/ATLAS represents the third confirmed visitor from outside the Solar System. Despite extensive international observations aimed at characterizing its chemical activity, dust production, and dynamical behavior, no direct or indirect measurement of its magnetic field has been performed. Magnetic diagnostics — including Zeeman splitting, circular polarization, Faraday rotation, synchrotron signatures, or magnetometer readings — are completely absent from the scientific literature. This review provides the first systematic assessment of all publicly available datasets and archival resources capable of detecting magnetic signatures. High-resolution optical spectrographs (UVES, HIRES, X-shooter), ground-based polarimeters (FORS2, HARPS-Pol, ESPaDOnS), and radio observatories (VLA, MeerKAT, ALMA) were evaluated. No observatory performed Zeeman-mode observations, no polarimetric campaign was scheduled, and no radio dataset has been analyzed for magnetic splitting. The optimal detection window (September–November 2025) passed without any magnetic measurements. These findings demonstrate a complete observational gap in the magnetic characterization of 3I/ATLAS and identify opportunities for re-analysis of unprocessed archival datasets. The study highlights the need for coordinated magnetic diagnostics in future interstellar-object encounters.