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

TL;DR

This paper analyzes interstellar comet 3I/ATLAS by combining nucleus size constraints with new RGB imaging of its anti-tail, providing insights into its dust structure and physical properties.

Contribution

It presents a unified analysis integrating existing nucleus size constraints with new ground-based RGB imaging of the anti-tail.

Findings

Nucleus size constraints derived from high-resolution imaging.

Detailed analysis of the anti-tail structure.

Insights into dust production and composition.

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).