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arXiv · 2604.18773

Linking System of Jets to the Non-Gravitational Acceleration of 3I/ATLAS

Abstract

Building on the jet morphology and periodic wobble analysis of 3I/ATLAS in Scarmato & Loeb (2026), we link observed jet position angles (PAs) and the non-gravitational acceleration components (A1,A2,A3) in the 3D RTN (radial, transverse, normal) frame relative to the Sun. We: (i) compute RTN directions from heliocentric state vectors and project them on the sky at the measured astromet ric pointings; (ii) compare projected RTN PAs to three persistent jets (Jet1-Jet2-Jet3) and quantify angular offsets; and (iii) estimate order-of-magnitude thrust and accelerations from HST/WFC3-UVIS F350LP net counts via transformations from photometry to cross-section, dust mass, mass-loss rate, and thrust. We explicitly document the uncertainties through background handling, phase-function systematics, and geometric degeneracies along the line of sight. For U.T. 2025-11-30.80903, Jet2 is aligned with the projected transverse direction to within 0.5 degs, while Jet3 is the closest to the pro jected normal direction with a moderate offset (about 25 degs). For UT 2025-12-27, Jet2 exhibits a monotonic PA drift over 24 minutes with a larger oscillation amplitude.

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Toni Scarmato, Abraham Loeb. 2026-04-20. Linking System of Jets to the Non-Gravitational Acceleration of 3I/ATLAS. https://arxiv.org/abs/2604.18773

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