Determine whether the 3I/ATLAS tail aligns more closely with the antisolar or anti-velocity direction

Ascertain whether the eastward tail extension of interstellar comet 3I/ATLAS is more closely aligned with the projected antisolar direction (-S) or with the negative heliocentric velocity vector (-V), based on position-angle measurements of pre-perihelion coma asymmetries.

Background

The paper analyzes the evolving morphology of 3I/ATLAS from a sunward fan to an antisolar tail and measures position angles of asymmetries relative to the projected antisolar (-S) and anti-velocity (-V) vectors.

Due to measurement uncertainties, the authors could not definitively identify whether the tail aligned more closely with -S or -V, although they note a slight preference for -V, which would be characteristic of large, slowly ejected particles that follow the orbit.