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arXiv · 2512.22365

Interstellar Interloper 3I/ATLAS: Nucleus Size, Photometry in RGB, Af(rho) and Antitail Structure Analysis

Toni Scarmato
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Abstract

Interstellar comet 3I/ATLAS (C/2025 N1) exhibits an unusual, tightly collimated dust feature in the sunward hemisphere which has been widely described as an anti-tail. At the same time, precise constraints on the nucleus size have been derived from a combination of high-resolution imaging and non-gravitational dynamics. In this work I present a unified analysis that combines existing constraints on the nucleus radius with new ground-based RGB imaging of the dust anti-tail obtained with a 0.25 m telescope at the Toni Scarmato Astronomical Observatory (MPC L92).

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Toni Scarmato. 2025-12-26. Interstellar Interloper 3I/ATLAS: Nucleus Size, Photometry in RGB, Af(rho) and Antitail Structure Analysis. https://arxiv.org/abs/2512.22365

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