HI envelope around the carbon star V420 Vul

We report the detection of an extended 21-cm parsec-scale i structure toward the Mira variable V420,Vul using archival Galactic Arecibo L-band Feed Array survey data. The emission exhibits a spatially coherent but intensity-asymmetric morphology that nevertheless retains a globally symmetric kinematic profile centered near v LSR about 47.6, km,s-1. At an adopted distance of about 1.9,kpc, the structure extends over about 20,pc, implying a dynamical timescale of order 10 6,yr. Although the total i mass (about 70, M) indicates that the atomic gas reservoir is heavily dominated by the ambient interstellar medium rather than pristine stellar ejecta, the spatially resolved spectra and position-velocity diagrams reveal an underlying symmetric velocity framework centered on the star. We interpret this as the dynamical imprint of the stellar wind preferentially channeling through a porous ambient cloud, demonstrating that cohesive kinematic records of late-stage stellar mass loss can be preserved over parsec scales and megayear timescales despite dominant interstellar coupling.